creation_sourcecode: // SPDX-License-Identifier: MIT
  
  // File @openzeppelin/contracts/utils/Context.sol@v4.9.6
  
  // Original license: SPDX_License_Identifier: MIT
  // OpenZeppelin Contracts (last updated v4.9.4) (utils/Context.sol)
  
  pragma solidity ^0.8.0;
  
  /**
   * @dev Provides information about the current execution context, including the
   * sender of the transaction and its data. While these are generally available
   * via msg.sender and msg.data, they should not be accessed in such a direct
   * manner, since when dealing with meta-transactions the account sending and
   * paying for execution may not be the actual sender (as far as an application
   * is concerned).
   *
   * This contract is only required for intermediate, library-like contracts.
   */
  abstract contract Context {
      function _msgSender() internal view virtual returns (address) {
          return msg.sender;
      }
  
      function _msgData() internal view virtual returns (bytes calldata) {
          return msg.data;
      }
  
      function _contextSuffixLength() internal view virtual returns (uint256) {
          return 0;
      }
  }
  
  
  // File @openzeppelin/contracts/access/Ownable.sol@v4.9.6
  
  // Original license: SPDX_License_Identifier: MIT
  // OpenZeppelin Contracts (last updated v4.9.0) (access/Ownable.sol)
  
  pragma solidity ^0.8.0;
  
  /**
   * @dev Contract module which provides a basic access control mechanism, where
   * there is an account (an owner) that can be granted exclusive access to
   * specific functions.
   *
   * By default, the owner account will be the one that deploys the contract. This
   * can later be changed with {transferOwnership}.
   *
   * This module is used through inheritance. It will make available the modifier
   * `onlyOwner`, which can be applied to your functions to restrict their use to
   * the owner.
   */
  abstract contract Ownable is Context {
      address private _owner;
  
      event OwnershipTransferred(address indexed previousOwner, address indexed newOwner);
  
      /**
       * @dev Initializes the contract setting the deployer as the initial owner.
       */
      constructor() {
          _transferOwnership(_msgSender());
      }
  
      /**
       * @dev Throws if called by any account other than the owner.
       */
      modifier onlyOwner() {
          _checkOwner();
          _;
      }
  
      /**
       * @dev Returns the address of the current owner.
       */
      function owner() public view virtual returns (address) {
          return _owner;
      }
  
      /**
       * @dev Throws if the sender is not the owner.
       */
      function _checkOwner() internal view virtual {
          require(owner() == _msgSender(), "Ownable: caller is not the owner");
      }
  
      /**
       * @dev Leaves the contract without owner. It will not be possible to call
       * `onlyOwner` functions. Can only be called by the current owner.
       *
       * NOTE: Renouncing ownership will leave the contract without an owner,
       * thereby disabling any functionality that is only available to the owner.
       */
      function renounceOwnership() public virtual onlyOwner {
          _transferOwnership(address(0));
      }
  
      /**
       * @dev Transfers ownership of the contract to a new account (`newOwner`).
       * Can only be called by the current owner.
       */
      function transferOwnership(address newOwner) public virtual onlyOwner {
          require(newOwner != address(0), "Ownable: new owner is the zero address");
          _transferOwnership(newOwner);
      }
  
      /**
       * @dev Transfers ownership of the contract to a new account (`newOwner`).
       * Internal function without access restriction.
       */
      function _transferOwnership(address newOwner) internal virtual {
          address oldOwner = _owner;
          _owner = newOwner;
          emit OwnershipTransferred(oldOwner, newOwner);
      }
  }
  
  
  // File @openzeppelin/contracts/access/Ownable2Step.sol@v4.9.6
  
  // Original license: SPDX_License_Identifier: MIT
  // OpenZeppelin Contracts (last updated v4.9.0) (access/Ownable2Step.sol)
  
  pragma solidity ^0.8.0;
  
  /**
   * @dev Contract module which provides access control mechanism, where
   * there is an account (an owner) that can be granted exclusive access to
   * specific functions.
   *
   * By default, the owner account will be the one that deploys the contract. This
   * can later be changed with {transferOwnership} and {acceptOwnership}.
   *
   * This module is used through inheritance. It will make available all functions
   * from parent (Ownable).
   */
  abstract contract Ownable2Step is Ownable {
      address private _pendingOwner;
  
      event OwnershipTransferStarted(address indexed previousOwner, address indexed newOwner);
  
      /**
       * @dev Returns the address of the pending owner.
       */
      function pendingOwner() public view virtual returns (address) {
          return _pendingOwner;
      }
  
      /**
       * @dev Starts the ownership transfer of the contract to a new account. Replaces the pending transfer if there is one.
       * Can only be called by the current owner.
       */
      function transferOwnership(address newOwner) public virtual override onlyOwner {
          _pendingOwner = newOwner;
          emit OwnershipTransferStarted(owner(), newOwner);
      }
  
      /**
       * @dev Transfers ownership of the contract to a new account (`newOwner`) and deletes any pending owner.
       * Internal function without access restriction.
       */
      function _transferOwnership(address newOwner) internal virtual override {
          delete _pendingOwner;
          super._transferOwnership(newOwner);
      }
  
      /**
       * @dev The new owner accepts the ownership transfer.
       */
      function acceptOwnership() public virtual {
          address sender = _msgSender();
          require(pendingOwner() == sender, "Ownable2Step: caller is not the new owner");
          _transferOwnership(sender);
      }
  }
  
  
  // File @openzeppelin/contracts/token/ERC20/IERC20.sol@v4.9.6
  
  // Original license: SPDX_License_Identifier: MIT
  // OpenZeppelin Contracts (last updated v4.9.0) (token/ERC20/IERC20.sol)
  
  pragma solidity ^0.8.0;
  
  /**
   * @dev Interface of the ERC20 standard as defined in the EIP.
   */
  interface IERC20 {
      /**
       * @dev Emitted when `value` tokens are moved from one account (`from`) to
       * another (`to`).
       *
       * Note that `value` may be zero.
       */
      event Transfer(address indexed from, address indexed to, uint256 value);
  
      /**
       * @dev Emitted when the allowance of a `spender` for an `owner` is set by
       * a call to {approve}. `value` is the new allowance.
       */
      event Approval(address indexed owner, address indexed spender, uint256 value);
  
      /**
       * @dev Returns the amount of tokens in existence.
       */
      function totalSupply() external view returns (uint256);
  
      /**
       * @dev Returns the amount of tokens owned by `account`.
       */
      function balanceOf(address account) external view returns (uint256);
  
      /**
       * @dev Moves `amount` tokens from the caller's account to `to`.
       *
       * Returns a boolean value indicating whether the operation succeeded.
       *
       * Emits a {Transfer} event.
       */
      function transfer(address to, uint256 amount) external returns (bool);
  
      /**
       * @dev Returns the remaining number of tokens that `spender` will be
       * allowed to spend on behalf of `owner` through {transferFrom}. This is
       * zero by default.
       *
       * This value changes when {approve} or {transferFrom} are called.
       */
      function allowance(address owner, address spender) external view returns (uint256);
  
      /**
       * @dev Sets `amount` as the allowance of `spender` over the caller's tokens.
       *
       * Returns a boolean value indicating whether the operation succeeded.
       *
       * IMPORTANT: Beware that changing an allowance with this method brings the risk
       * that someone may use both the old and the new allowance by unfortunate
       * transaction ordering. One possible solution to mitigate this race
       * condition is to first reduce the spender's allowance to 0 and set the
       * desired value afterwards:
       * https://github.com/ethereum/EIPs/issues/20#issuecomment-263524729
       *
       * Emits an {Approval} event.
       */
      function approve(address spender, uint256 amount) external returns (bool);
  
      /**
       * @dev Moves `amount` tokens from `from` to `to` using the
       * allowance mechanism. `amount` is then deducted from the caller's
       * allowance.
       *
       * Returns a boolean value indicating whether the operation succeeded.
       *
       * Emits a {Transfer} event.
       */
      function transferFrom(address from, address to, uint256 amount) external returns (bool);
  }
  
  
  // File @openzeppelin/contracts/token/ERC20/extensions/IERC20Metadata.sol@v4.9.6
  
  // Original license: SPDX_License_Identifier: MIT
  // OpenZeppelin Contracts v4.4.1 (token/ERC20/extensions/IERC20Metadata.sol)
  
  pragma solidity ^0.8.0;
  
  /**
   * @dev Interface for the optional metadata functions from the ERC20 standard.
   *
   * _Available since v4.1._
   */
  interface IERC20Metadata is IERC20 {
      /**
       * @dev Returns the name of the token.
       */
      function name() external view returns (string memory);
  
      /**
       * @dev Returns the symbol of the token.
       */
      function symbol() external view returns (string memory);
  
      /**
       * @dev Returns the decimals places of the token.
       */
      function decimals() external view returns (uint8);
  }
  
  
  // File @openzeppelin/contracts/interfaces/IERC20Metadata.sol@v4.9.6
  
  // Original license: SPDX_License_Identifier: MIT
  // OpenZeppelin Contracts v4.4.1 (interfaces/IERC20Metadata.sol)
  
  pragma solidity ^0.8.0;
  
  
  // File @openzeppelin/contracts/interfaces/IERC4626.sol@v4.9.6
  
  // Original license: SPDX_License_Identifier: MIT
  // OpenZeppelin Contracts (last updated v4.9.0) (interfaces/IERC4626.sol)
  
  pragma solidity ^0.8.0;
  
  
  /**
   * @dev Interface of the ERC4626 "Tokenized Vault Standard", as defined in
   * https://eips.ethereum.org/EIPS/eip-4626[ERC-4626].
   *
   * _Available since v4.7._
   */
  interface IERC4626 is IERC20, IERC20Metadata {
      event Deposit(address indexed sender, address indexed owner, uint256 assets, uint256 shares);
  
      event Withdraw(
          address indexed sender,
          address indexed receiver,
          address indexed owner,
          uint256 assets,
          uint256 shares
      );
  
      /**
       * @dev Returns the address of the underlying token used for the Vault for accounting, depositing, and withdrawing.
       *
       * - MUST be an ERC-20 token contract.
       * - MUST NOT revert.
       */
      function asset() external view returns (address assetTokenAddress);
  
      /**
       * @dev Returns the total amount of the underlying asset that is “managed” by Vault.
       *
       * - SHOULD include any compounding that occurs from yield.
       * - MUST be inclusive of any fees that are charged against assets in the Vault.
       * - MUST NOT revert.
       */
      function totalAssets() external view returns (uint256 totalManagedAssets);
  
      /**
       * @dev Returns the amount of shares that the Vault would exchange for the amount of assets provided, in an ideal
       * scenario where all the conditions are met.
       *
       * - MUST NOT be inclusive of any fees that are charged against assets in the Vault.
       * - MUST NOT show any variations depending on the caller.
       * - MUST NOT reflect slippage or other on-chain conditions, when performing the actual exchange.
       * - MUST NOT revert.
       *
       * NOTE: This calculation MAY NOT reflect the “per-user” price-per-share, and instead should reflect the
       * “average-user’s” price-per-share, meaning what the average user should expect to see when exchanging to and
       * from.
       */
      function convertToShares(uint256 assets) external view returns (uint256 shares);
  
      /**
       * @dev Returns the amount of assets that the Vault would exchange for the amount of shares provided, in an ideal
       * scenario where all the conditions are met.
       *
       * - MUST NOT be inclusive of any fees that are charged against assets in the Vault.
       * - MUST NOT show any variations depending on the caller.
       * - MUST NOT reflect slippage or other on-chain conditions, when performing the actual exchange.
       * - MUST NOT revert.
       *
       * NOTE: This calculation MAY NOT reflect the “per-user” price-per-share, and instead should reflect the
       * “average-user’s” price-per-share, meaning what the average user should expect to see when exchanging to and
       * from.
       */
      function convertToAssets(uint256 shares) external view returns (uint256 assets);
  
      /**
       * @dev Returns the maximum amount of the underlying asset that can be deposited into the Vault for the receiver,
       * through a deposit call.
       *
       * - MUST return a limited value if receiver is subject to some deposit limit.
       * - MUST return 2 ** 256 - 1 if there is no limit on the maximum amount of assets that may be deposited.
       * - MUST NOT revert.
       */
      function maxDeposit(address receiver) external view returns (uint256 maxAssets);
  
      /**
       * @dev Allows an on-chain or off-chain user to simulate the effects of their deposit at the current block, given
       * current on-chain conditions.
       *
       * - MUST return as close to and no more than the exact amount of Vault shares that would be minted in a deposit
       *   call in the same transaction. I.e. deposit should return the same or more shares as previewDeposit if called
       *   in the same transaction.
       * - MUST NOT account for deposit limits like those returned from maxDeposit and should always act as though the
       *   deposit would be accepted, regardless if the user has enough tokens approved, etc.
       * - MUST be inclusive of deposit fees. Integrators should be aware of the existence of deposit fees.
       * - MUST NOT revert.
       *
       * NOTE: any unfavorable discrepancy between convertToShares and previewDeposit SHOULD be considered slippage in
       * share price or some other type of condition, meaning the depositor will lose assets by depositing.
       */
      function previewDeposit(uint256 assets) external view returns (uint256 shares);
  
      /**
       * @dev Mints shares Vault shares to receiver by depositing exactly amount of underlying tokens.
       *
       * - MUST emit the Deposit event.
       * - MAY support an additional flow in which the underlying tokens are owned by the Vault contract before the
       *   deposit execution, and are accounted for during deposit.
       * - MUST revert if all of assets cannot be deposited (due to deposit limit being reached, slippage, the user not
       *   approving enough underlying tokens to the Vault contract, etc).
       *
       * NOTE: most implementations will require pre-approval of the Vault with the Vault’s underlying asset token.
       */
      function deposit(uint256 assets, address receiver) external returns (uint256 shares);
  
      /**
       * @dev Returns the maximum amount of the Vault shares that can be minted for the receiver, through a mint call.
       * - MUST return a limited value if receiver is subject to some mint limit.
       * - MUST return 2 ** 256 - 1 if there is no limit on the maximum amount of shares that may be minted.
       * - MUST NOT revert.
       */
      function maxMint(address receiver) external view returns (uint256 maxShares);
  
      /**
       * @dev Allows an on-chain or off-chain user to simulate the effects of their mint at the current block, given
       * current on-chain conditions.
       *
       * - MUST return as close to and no fewer than the exact amount of assets that would be deposited in a mint call
       *   in the same transaction. I.e. mint should return the same or fewer assets as previewMint if called in the
       *   same transaction.
       * - MUST NOT account for mint limits like those returned from maxMint and should always act as though the mint
       *   would be accepted, regardless if the user has enough tokens approved, etc.
       * - MUST be inclusive of deposit fees. Integrators should be aware of the existence of deposit fees.
       * - MUST NOT revert.
       *
       * NOTE: any unfavorable discrepancy between convertToAssets and previewMint SHOULD be considered slippage in
       * share price or some other type of condition, meaning the depositor will lose assets by minting.
       */
      function previewMint(uint256 shares) external view returns (uint256 assets);
  
      /**
       * @dev Mints exactly shares Vault shares to receiver by depositing amount of underlying tokens.
       *
       * - MUST emit the Deposit event.
       * - MAY support an additional flow in which the underlying tokens are owned by the Vault contract before the mint
       *   execution, and are accounted for during mint.
       * - MUST revert if all of shares cannot be minted (due to deposit limit being reached, slippage, the user not
       *   approving enough underlying tokens to the Vault contract, etc).
       *
       * NOTE: most implementations will require pre-approval of the Vault with the Vault’s underlying asset token.
       */
      function mint(uint256 shares, address receiver) external returns (uint256 assets);
  
      /**
       * @dev Returns the maximum amount of the underlying asset that can be withdrawn from the owner balance in the
       * Vault, through a withdraw call.
       *
       * - MUST return a limited value if owner is subject to some withdrawal limit or timelock.
       * - MUST NOT revert.
       */
      function maxWithdraw(address owner) external view returns (uint256 maxAssets);
  
      /**
       * @dev Allows an on-chain or off-chain user to simulate the effects of their withdrawal at the current block,
       * given current on-chain conditions.
       *
       * - MUST return as close to and no fewer than the exact amount of Vault shares that would be burned in a withdraw
       *   call in the same transaction. I.e. withdraw should return the same or fewer shares as previewWithdraw if
       *   called
       *   in the same transaction.
       * - MUST NOT account for withdrawal limits like those returned from maxWithdraw and should always act as though
       *   the withdrawal would be accepted, regardless if the user has enough shares, etc.
       * - MUST be inclusive of withdrawal fees. Integrators should be aware of the existence of withdrawal fees.
       * - MUST NOT revert.
       *
       * NOTE: any unfavorable discrepancy between convertToShares and previewWithdraw SHOULD be considered slippage in
       * share price or some other type of condition, meaning the depositor will lose assets by depositing.
       */
      function previewWithdraw(uint256 assets) external view returns (uint256 shares);
  
      /**
       * @dev Burns shares from owner and sends exactly assets of underlying tokens to receiver.
       *
       * - MUST emit the Withdraw event.
       * - MAY support an additional flow in which the underlying tokens are owned by the Vault contract before the
       *   withdraw execution, and are accounted for during withdraw.
       * - MUST revert if all of assets cannot be withdrawn (due to withdrawal limit being reached, slippage, the owner
       *   not having enough shares, etc).
       *
       * Note that some implementations will require pre-requesting to the Vault before a withdrawal may be performed.
       * Those methods should be performed separately.
       */
      function withdraw(uint256 assets, address receiver, address owner) external returns (uint256 shares);
  
      /**
       * @dev Returns the maximum amount of Vault shares that can be redeemed from the owner balance in the Vault,
       * through a redeem call.
       *
       * - MUST return a limited value if owner is subject to some withdrawal limit or timelock.
       * - MUST return balanceOf(owner) if owner is not subject to any withdrawal limit or timelock.
       * - MUST NOT revert.
       */
      function maxRedeem(address owner) external view returns (uint256 maxShares);
  
      /**
       * @dev Allows an on-chain or off-chain user to simulate the effects of their redeemption at the current block,
       * given current on-chain conditions.
       *
       * - MUST return as close to and no more than the exact amount of assets that would be withdrawn in a redeem call
       *   in the same transaction. I.e. redeem should return the same or more assets as previewRedeem if called in the
       *   same transaction.
       * - MUST NOT account for redemption limits like those returned from maxRedeem and should always act as though the
       *   redemption would be accepted, regardless if the user has enough shares, etc.
       * - MUST be inclusive of withdrawal fees. Integrators should be aware of the existence of withdrawal fees.
       * - MUST NOT revert.
       *
       * NOTE: any unfavorable discrepancy between convertToAssets and previewRedeem SHOULD be considered slippage in
       * share price or some other type of condition, meaning the depositor will lose assets by redeeming.
       */
      function previewRedeem(uint256 shares) external view returns (uint256 assets);
  
      /**
       * @dev Burns exactly shares from owner and sends assets of underlying tokens to receiver.
       *
       * - MUST emit the Withdraw event.
       * - MAY support an additional flow in which the underlying tokens are owned by the Vault contract before the
       *   redeem execution, and are accounted for during redeem.
       * - MUST revert if all of shares cannot be redeemed (due to withdrawal limit being reached, slippage, the owner
       *   not having enough shares, etc).
       *
       * NOTE: some implementations will require pre-requesting to the Vault before a withdrawal may be performed.
       * Those methods should be performed separately.
       */
      function redeem(uint256 shares, address receiver, address owner) external returns (uint256 assets);
  }
  
  
  // File @openzeppelin/contracts/token/ERC20/ERC20.sol@v4.9.6
  
  // Original license: SPDX_License_Identifier: MIT
  // OpenZeppelin Contracts (last updated v4.9.0) (token/ERC20/ERC20.sol)
  
  pragma solidity ^0.8.0;
  
  
  
  /**
   * @dev Implementation of the {IERC20} interface.
   *
   * This implementation is agnostic to the way tokens are created. This means
   * that a supply mechanism has to be added in a derived contract using {_mint}.
   * For a generic mechanism see {ERC20PresetMinterPauser}.
   *
   * TIP: For a detailed writeup see our guide
   * https://forum.openzeppelin.com/t/how-to-implement-erc20-supply-mechanisms/226[How
   * to implement supply mechanisms].
   *
   * The default value of {decimals} is 18. To change this, you should override
   * this function so it returns a different value.
   *
   * We have followed general OpenZeppelin Contracts guidelines: functions revert
   * instead returning `false` on failure. This behavior is nonetheless
   * conventional and does not conflict with the expectations of ERC20
   * applications.
   *
   * Additionally, an {Approval} event is emitted on calls to {transferFrom}.
   * This allows applications to reconstruct the allowance for all accounts just
   * by listening to said events. Other implementations of the EIP may not emit
   * these events, as it isn't required by the specification.
   *
   * Finally, the non-standard {decreaseAllowance} and {increaseAllowance}
   * functions have been added to mitigate the well-known issues around setting
   * allowances. See {IERC20-approve}.
   */
  contract ERC20 is Context, IERC20, IERC20Metadata {
      mapping(address => uint256) private _balances;
  
      mapping(address => mapping(address => uint256)) private _allowances;
  
      uint256 private _totalSupply;
  
      string private _name;
      string private _symbol;
  
      /**
       * @dev Sets the values for {name} and {symbol}.
       *
       * All two of these values are immutable: they can only be set once during
       * construction.
       */
      constructor(string memory name_, string memory symbol_) {
          _name = name_;
          _symbol = symbol_;
      }
  
      /**
       * @dev Returns the name of the token.
       */
      function name() public view virtual override returns (string memory) {
          return _name;
      }
  
      /**
       * @dev Returns the symbol of the token, usually a shorter version of the
       * name.
       */
      function symbol() public view virtual override returns (string memory) {
          return _symbol;
      }
  
      /**
       * @dev Returns the number of decimals used to get its user representation.
       * For example, if `decimals` equals `2`, a balance of `505` tokens should
       * be displayed to a user as `5.05` (`505 / 10 ** 2`).
       *
       * Tokens usually opt for a value of 18, imitating the relationship between
       * Ether and Wei. This is the default value returned by this function, unless
       * it's overridden.
       *
       * NOTE: This information is only used for _display_ purposes: it in
       * no way affects any of the arithmetic of the contract, including
       * {IERC20-balanceOf} and {IERC20-transfer}.
       */
      function decimals() public view virtual override returns (uint8) {
          return 18;
      }
  
      /**
       * @dev See {IERC20-totalSupply}.
       */
      function totalSupply() public view virtual override returns (uint256) {
          return _totalSupply;
      }
  
      /**
       * @dev See {IERC20-balanceOf}.
       */
      function balanceOf(address account) public view virtual override returns (uint256) {
          return _balances[account];
      }
  
      /**
       * @dev See {IERC20-transfer}.
       *
       * Requirements:
       *
       * - `to` cannot be the zero address.
       * - the caller must have a balance of at least `amount`.
       */
      function transfer(address to, uint256 amount) public virtual override returns (bool) {
          address owner = _msgSender();
          _transfer(owner, to, amount);
          return true;
      }
  
      /**
       * @dev See {IERC20-allowance}.
       */
      function allowance(address owner, address spender) public view virtual override returns (uint256) {
          return _allowances[owner][spender];
      }
  
      /**
       * @dev See {IERC20-approve}.
       *
       * NOTE: If `amount` is the maximum `uint256`, the allowance is not updated on
       * `transferFrom`. This is semantically equivalent to an infinite approval.
       *
       * Requirements:
       *
       * - `spender` cannot be the zero address.
       */
      function approve(address spender, uint256 amount) public virtual override returns (bool) {
          address owner = _msgSender();
          _approve(owner, spender, amount);
          return true;
      }
  
      /**
       * @dev See {IERC20-transferFrom}.
       *
       * Emits an {Approval} event indicating the updated allowance. This is not
       * required by the EIP. See the note at the beginning of {ERC20}.
       *
       * NOTE: Does not update the allowance if the current allowance
       * is the maximum `uint256`.
       *
       * Requirements:
       *
       * - `from` and `to` cannot be the zero address.
       * - `from` must have a balance of at least `amount`.
       * - the caller must have allowance for ``from``'s tokens of at least
       * `amount`.
       */
      function transferFrom(address from, address to, uint256 amount) public virtual override returns (bool) {
          address spender = _msgSender();
          _spendAllowance(from, spender, amount);
          _transfer(from, to, amount);
          return true;
      }
  
      /**
       * @dev Atomically increases the allowance granted to `spender` by the caller.
       *
       * This is an alternative to {approve} that can be used as a mitigation for
       * problems described in {IERC20-approve}.
       *
       * Emits an {Approval} event indicating the updated allowance.
       *
       * Requirements:
       *
       * - `spender` cannot be the zero address.
       */
      function increaseAllowance(address spender, uint256 addedValue) public virtual returns (bool) {
          address owner = _msgSender();
          _approve(owner, spender, allowance(owner, spender) + addedValue);
          return true;
      }
  
      /**
       * @dev Atomically decreases the allowance granted to `spender` by the caller.
       *
       * This is an alternative to {approve} that can be used as a mitigation for
       * problems described in {IERC20-approve}.
       *
       * Emits an {Approval} event indicating the updated allowance.
       *
       * Requirements:
       *
       * - `spender` cannot be the zero address.
       * - `spender` must have allowance for the caller of at least
       * `subtractedValue`.
       */
      function decreaseAllowance(address spender, uint256 subtractedValue) public virtual returns (bool) {
          address owner = _msgSender();
          uint256 currentAllowance = allowance(owner, spender);
          require(currentAllowance >= subtractedValue, "ERC20: decreased allowance below zero");
          unchecked {
              _approve(owner, spender, currentAllowance - subtractedValue);
          }
  
          return true;
      }
  
      /**
       * @dev Moves `amount` of tokens from `from` to `to`.
       *
       * This internal function is equivalent to {transfer}, and can be used to
       * e.g. implement automatic token fees, slashing mechanisms, etc.
       *
       * Emits a {Transfer} event.
       *
       * Requirements:
       *
       * - `from` cannot be the zero address.
       * - `to` cannot be the zero address.
       * - `from` must have a balance of at least `amount`.
       */
      function _transfer(address from, address to, uint256 amount) internal virtual {
          require(from != address(0), "ERC20: transfer from the zero address");
          require(to != address(0), "ERC20: transfer to the zero address");
  
          _beforeTokenTransfer(from, to, amount);
  
          uint256 fromBalance = _balances[from];
          require(fromBalance >= amount, "ERC20: transfer amount exceeds balance");
          unchecked {
              _balances[from] = fromBalance - amount;
              // Overflow not possible: the sum of all balances is capped by totalSupply, and the sum is preserved by
              // decrementing then incrementing.
              _balances[to] += amount;
          }
  
          emit Transfer(from, to, amount);
  
          _afterTokenTransfer(from, to, amount);
      }
  
      /** @dev Creates `amount` tokens and assigns them to `account`, increasing
       * the total supply.
       *
       * Emits a {Transfer} event with `from` set to the zero address.
       *
       * Requirements:
       *
       * - `account` cannot be the zero address.
       */
      function _mint(address account, uint256 amount) internal virtual {
          require(account != address(0), "ERC20: mint to the zero address");
  
          _beforeTokenTransfer(address(0), account, amount);
  
          _totalSupply += amount;
          unchecked {
              // Overflow not possible: balance + amount is at most totalSupply + amount, which is checked above.
              _balances[account] += amount;
          }
          emit Transfer(address(0), account, amount);
  
          _afterTokenTransfer(address(0), account, amount);
      }
  
      /**
       * @dev Destroys `amount` tokens from `account`, reducing the
       * total supply.
       *
       * Emits a {Transfer} event with `to` set to the zero address.
       *
       * Requirements:
       *
       * - `account` cannot be the zero address.
       * - `account` must have at least `amount` tokens.
       */
      function _burn(address account, uint256 amount) internal virtual {
          require(account != address(0), "ERC20: burn from the zero address");
  
          _beforeTokenTransfer(account, address(0), amount);
  
          uint256 accountBalance = _balances[account];
          require(accountBalance >= amount, "ERC20: burn amount exceeds balance");
          unchecked {
              _balances[account] = accountBalance - amount;
              // Overflow not possible: amount <= accountBalance <= totalSupply.
              _totalSupply -= amount;
          }
  
          emit Transfer(account, address(0), amount);
  
          _afterTokenTransfer(account, address(0), amount);
      }
  
      /**
       * @dev Sets `amount` as the allowance of `spender` over the `owner` s tokens.
       *
       * This internal function is equivalent to `approve`, and can be used to
       * e.g. set automatic allowances for certain subsystems, etc.
       *
       * Emits an {Approval} event.
       *
       * Requirements:
       *
       * - `owner` cannot be the zero address.
       * - `spender` cannot be the zero address.
       */
      function _approve(address owner, address spender, uint256 amount) internal virtual {
          require(owner != address(0), "ERC20: approve from the zero address");
          require(spender != address(0), "ERC20: approve to the zero address");
  
          _allowances[owner][spender] = amount;
          emit Approval(owner, spender, amount);
      }
  
      /**
       * @dev Updates `owner` s allowance for `spender` based on spent `amount`.
       *
       * Does not update the allowance amount in case of infinite allowance.
       * Revert if not enough allowance is available.
       *
       * Might emit an {Approval} event.
       */
      function _spendAllowance(address owner, address spender, uint256 amount) internal virtual {
          uint256 currentAllowance = allowance(owner, spender);
          if (currentAllowance != type(uint256).max) {
              require(currentAllowance >= amount, "ERC20: insufficient allowance");
              unchecked {
                  _approve(owner, spender, currentAllowance - amount);
              }
          }
      }
  
      /**
       * @dev Hook that is called before any transfer of tokens. This includes
       * minting and burning.
       *
       * Calling conditions:
       *
       * - when `from` and `to` are both non-zero, `amount` of ``from``'s tokens
       * will be transferred to `to`.
       * - when `from` is zero, `amount` tokens will be minted for `to`.
       * - when `to` is zero, `amount` of ``from``'s tokens will be burned.
       * - `from` and `to` are never both zero.
       *
       * To learn more about hooks, head to xref:ROOT:extending-contracts.adoc#using-hooks[Using Hooks].
       */
      function _beforeTokenTransfer(address from, address to, uint256 amount) internal virtual {}
  
      /**
       * @dev Hook that is called after any transfer of tokens. This includes
       * minting and burning.
       *
       * Calling conditions:
       *
       * - when `from` and `to` are both non-zero, `amount` of ``from``'s tokens
       * has been transferred to `to`.
       * - when `from` is zero, `amount` tokens have been minted for `to`.
       * - when `to` is zero, `amount` of ``from``'s tokens have been burned.
       * - `from` and `to` are never both zero.
       *
       * To learn more about hooks, head to xref:ROOT:extending-contracts.adoc#using-hooks[Using Hooks].
       */
      function _afterTokenTransfer(address from, address to, uint256 amount) internal virtual {}
  }
  
  
  // File @openzeppelin/contracts/token/ERC20/extensions/IERC20Permit.sol@v4.9.6
  
  // Original license: SPDX_License_Identifier: MIT
  // OpenZeppelin Contracts (last updated v4.9.4) (token/ERC20/extensions/IERC20Permit.sol)
  
  pragma solidity ^0.8.0;
  
  /**
   * @dev Interface of the ERC20 Permit extension allowing approvals to be made via signatures, as defined in
   * https://eips.ethereum.org/EIPS/eip-2612[EIP-2612].
   *
   * Adds the {permit} method, which can be used to change an account's ERC20 allowance (see {IERC20-allowance}) by
   * presenting a message signed by the account. By not relying on {IERC20-approve}, the token holder account doesn't
   * need to send a transaction, and thus is not required to hold Ether at all.
   *
   * ==== Security Considerations
   *
   * There are two important considerations concerning the use of `permit`. The first is that a valid permit signature
   * expresses an allowance, and it should not be assumed to convey additional meaning. In particular, it should not be
   * considered as an intention to spend the allowance in any specific way. The second is that because permits have
   * built-in replay protection and can be submitted by anyone, they can be frontrun. A protocol that uses permits should
   * take this into consideration and allow a `permit` call to fail. Combining these two aspects, a pattern that may be
   * generally recommended is:
   *
   * ```solidity
   * function doThingWithPermit(..., uint256 value, uint256 deadline, uint8 v, bytes32 r, bytes32 s) public {
   *     try token.permit(msg.sender, address(this), value, deadline, v, r, s) {} catch {}
   *     doThing(..., value);
   * }
   *
   * function doThing(..., uint256 value) public {
   *     token.safeTransferFrom(msg.sender, address(this), value);
   *     ...
   * }
   * ```
   *
   * Observe that: 1) `msg.sender` is used as the owner, leaving no ambiguity as to the signer intent, and 2) the use of
   * `try/catch` allows the permit to fail and makes the code tolerant to frontrunning. (See also
   * {SafeERC20-safeTransferFrom}).
   *
   * Additionally, note that smart contract wallets (such as Argent or Safe) are not able to produce permit signatures, so
   * contracts should have entry points that don't rely on permit.
   */
  interface IERC20Permit {
      /**
       * @dev Sets `value` as the allowance of `spender` over ``owner``'s tokens,
       * given ``owner``'s signed approval.
       *
       * IMPORTANT: The same issues {IERC20-approve} has related to transaction
       * ordering also apply here.
       *
       * Emits an {Approval} event.
       *
       * Requirements:
       *
       * - `spender` cannot be the zero address.
       * - `deadline` must be a timestamp in the future.
       * - `v`, `r` and `s` must be a valid `secp256k1` signature from `owner`
       * over the EIP712-formatted function arguments.
       * - the signature must use ``owner``'s current nonce (see {nonces}).
       *
       * For more information on the signature format, see the
       * https://eips.ethereum.org/EIPS/eip-2612#specification[relevant EIP
       * section].
       *
       * CAUTION: See Security Considerations above.
       */
      function permit(
          address owner,
          address spender,
          uint256 value,
          uint256 deadline,
          uint8 v,
          bytes32 r,
          bytes32 s
      ) external;
  
      /**
       * @dev Returns the current nonce for `owner`. This value must be
       * included whenever a signature is generated for {permit}.
       *
       * Every successful call to {permit} increases ``owner``'s nonce by one. This
       * prevents a signature from being used multiple times.
       */
      function nonces(address owner) external view returns (uint256);
  
      /**
       * @dev Returns the domain separator used in the encoding of the signature for {permit}, as defined by {EIP712}.
       */
      // solhint-disable-next-line func-name-mixedcase
      function DOMAIN_SEPARATOR() external view returns (bytes32);
  }
  
  
  // File @openzeppelin/contracts/utils/Address.sol@v4.9.6
  
  // Original license: SPDX_License_Identifier: MIT
  // OpenZeppelin Contracts (last updated v4.9.0) (utils/Address.sol)
  
  pragma solidity ^0.8.1;
  
  /**
   * @dev Collection of functions related to the address type
   */
  library Address {
      /**
       * @dev Returns true if `account` is a contract.
       *
       * [IMPORTANT]
       * ====
       * It is unsafe to assume that an address for which this function returns
       * false is an externally-owned account (EOA) and not a contract.
       *
       * Among others, `isContract` will return false for the following
       * types of addresses:
       *
       *  - an externally-owned account
       *  - a contract in construction
       *  - an address where a contract will be created
       *  - an address where a contract lived, but was destroyed
       *
       * Furthermore, `isContract` will also return true if the target contract within
       * the same transaction is already scheduled for destruction by `SELFDESTRUCT`,
       * which only has an effect at the end of a transaction.
       * ====
       *
       * [IMPORTANT]
       * ====
       * You shouldn't rely on `isContract` to protect against flash loan attacks!
       *
       * Preventing calls from contracts is highly discouraged. It breaks composability, breaks support for smart wallets
       * like Gnosis Safe, and does not provide security since it can be circumvented by calling from a contract
       * constructor.
       * ====
       */
      function isContract(address account) internal view returns (bool) {
          // This method relies on extcodesize/address.code.length, which returns 0
          // for contracts in construction, since the code is only stored at the end
          // of the constructor execution.
  
          return account.code.length > 0;
      }
  
      /**
       * @dev Replacement for Solidity's `transfer`: sends `amount` wei to
       * `recipient`, forwarding all available gas and reverting on errors.
       *
       * https://eips.ethereum.org/EIPS/eip-1884[EIP1884] increases the gas cost
       * of certain opcodes, possibly making contracts go over the 2300 gas limit
       * imposed by `transfer`, making them unable to receive funds via
       * `transfer`. {sendValue} removes this limitation.
       *
       * https://consensys.net/diligence/blog/2019/09/stop-using-soliditys-transfer-now/[Learn more].
       *
       * IMPORTANT: because control is transferred to `recipient`, care must be
       * taken to not create reentrancy vulnerabilities. Consider using
       * {ReentrancyGuard} or the
       * https://solidity.readthedocs.io/en/v0.8.0/security-considerations.html#use-the-checks-effects-interactions-pattern[checks-effects-interactions pattern].
       */
      function sendValue(address payable recipient, uint256 amount) internal {
          require(address(this).balance >= amount, "Address: insufficient balance");
  
          (bool success, ) = recipient.call{value: amount}("");
          require(success, "Address: unable to send value, recipient may have reverted");
      }
  
      /**
       * @dev Performs a Solidity function call using a low level `call`. A
       * plain `call` is an unsafe replacement for a function call: use this
       * function instead.
       *
       * If `target` reverts with a revert reason, it is bubbled up by this
       * function (like regular Solidity function calls).
       *
       * Returns the raw returned data. To convert to the expected return value,
       * use https://solidity.readthedocs.io/en/latest/units-and-global-variables.html?highlight=abi.decode#abi-encoding-and-decoding-functions[`abi.decode`].
       *
       * Requirements:
       *
       * - `target` must be a contract.
       * - calling `target` with `data` must not revert.
       *
       * _Available since v3.1._
       */
      function functionCall(address target, bytes memory data) internal returns (bytes memory) {
          return functionCallWithValue(target, data, 0, "Address: low-level call failed");
      }
  
      /**
       * @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`], but with
       * `errorMessage` as a fallback revert reason when `target` reverts.
       *
       * _Available since v3.1._
       */
      function functionCall(
          address target,
          bytes memory data,
          string memory errorMessage
      ) internal returns (bytes memory) {
          return functionCallWithValue(target, data, 0, errorMessage);
      }
  
      /**
       * @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`],
       * but also transferring `value` wei to `target`.
       *
       * Requirements:
       *
       * - the calling contract must have an ETH balance of at least `value`.
       * - the called Solidity function must be `payable`.
       *
       * _Available since v3.1._
       */
      function functionCallWithValue(address target, bytes memory data, uint256 value) internal returns (bytes memory) {
          return functionCallWithValue(target, data, value, "Address: low-level call with value failed");
      }
  
      /**
       * @dev Same as {xref-Address-functionCallWithValue-address-bytes-uint256-}[`functionCallWithValue`], but
       * with `errorMessage` as a fallback revert reason when `target` reverts.
       *
       * _Available since v3.1._
       */
      function functionCallWithValue(
          address target,
          bytes memory data,
          uint256 value,
          string memory errorMessage
      ) internal returns (bytes memory) {
          require(address(this).balance >= value, "Address: insufficient balance for call");
          (bool success, bytes memory returndata) = target.call{value: value}(data);
          return verifyCallResultFromTarget(target, success, returndata, errorMessage);
      }
  
      /**
       * @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`],
       * but performing a static call.
       *
       * _Available since v3.3._
       */
      function functionStaticCall(address target, bytes memory data) internal view returns (bytes memory) {
          return functionStaticCall(target, data, "Address: low-level static call failed");
      }
  
      /**
       * @dev Same as {xref-Address-functionCall-address-bytes-string-}[`functionCall`],
       * but performing a static call.
       *
       * _Available since v3.3._
       */
      function functionStaticCall(
          address target,
          bytes memory data,
          string memory errorMessage
      ) internal view returns (bytes memory) {
          (bool success, bytes memory returndata) = target.staticcall(data);
          return verifyCallResultFromTarget(target, success, returndata, errorMessage);
      }
  
      /**
       * @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`],
       * but performing a delegate call.
       *
       * _Available since v3.4._
       */
      function functionDelegateCall(address target, bytes memory data) internal returns (bytes memory) {
          return functionDelegateCall(target, data, "Address: low-level delegate call failed");
      }
  
      /**
       * @dev Same as {xref-Address-functionCall-address-bytes-string-}[`functionCall`],
       * but performing a delegate call.
       *
       * _Available since v3.4._
       */
      function functionDelegateCall(
          address target,
          bytes memory data,
          string memory errorMessage
      ) internal returns (bytes memory) {
          (bool success, bytes memory returndata) = target.delegatecall(data);
          return verifyCallResultFromTarget(target, success, returndata, errorMessage);
      }
  
      /**
       * @dev Tool to verify that a low level call to smart-contract was successful, and revert (either by bubbling
       * the revert reason or using the provided one) in case of unsuccessful call or if target was not a contract.
       *
       * _Available since v4.8._
       */
      function verifyCallResultFromTarget(
          address target,
          bool success,
          bytes memory returndata,
          string memory errorMessage
      ) internal view returns (bytes memory) {
          if (success) {
              if (returndata.length == 0) {
                  // only check isContract if the call was successful and the return data is empty
                  // otherwise we already know that it was a contract
                  require(isContract(target), "Address: call to non-contract");
              }
              return returndata;
          } else {
              _revert(returndata, errorMessage);
          }
      }
  
      /**
       * @dev Tool to verify that a low level call was successful, and revert if it wasn't, either by bubbling the
       * revert reason or using the provided one.
       *
       * _Available since v4.3._
       */
      function verifyCallResult(
          bool success,
          bytes memory returndata,
          string memory errorMessage
      ) internal pure returns (bytes memory) {
          if (success) {
              return returndata;
          } else {
              _revert(returndata, errorMessage);
          }
      }
  
      function _revert(bytes memory returndata, string memory errorMessage) private pure {
          // Look for revert reason and bubble it up if present
          if (returndata.length > 0) {
              // The easiest way to bubble the revert reason is using memory via assembly
              /// @solidity memory-safe-assembly
              assembly {
                  let returndata_size := mload(returndata)
                  revert(add(32, returndata), returndata_size)
              }
          } else {
              revert(errorMessage);
          }
      }
  }
  
  
  // File @openzeppelin/contracts/token/ERC20/utils/SafeERC20.sol@v4.9.6
  
  // Original license: SPDX_License_Identifier: MIT
  // OpenZeppelin Contracts (last updated v4.9.3) (token/ERC20/utils/SafeERC20.sol)
  
  pragma solidity ^0.8.0;
  
  
  
  /**
   * @title SafeERC20
   * @dev Wrappers around ERC20 operations that throw on failure (when the token
   * contract returns false). Tokens that return no value (and instead revert or
   * throw on failure) are also supported, non-reverting calls are assumed to be
   * successful.
   * To use this library you can add a `using SafeERC20 for IERC20;` statement to your contract,
   * which allows you to call the safe operations as `token.safeTransfer(...)`, etc.
   */
  library SafeERC20 {
      using Address for address;
  
      /**
       * @dev Transfer `value` amount of `token` from the calling contract to `to`. If `token` returns no value,
       * non-reverting calls are assumed to be successful.
       */
      function safeTransfer(IERC20 token, address to, uint256 value) internal {
          _callOptionalReturn(token, abi.encodeWithSelector(token.transfer.selector, to, value));
      }
  
      /**
       * @dev Transfer `value` amount of `token` from `from` to `to`, spending the approval given by `from` to the
       * calling contract. If `token` returns no value, non-reverting calls are assumed to be successful.
       */
      function safeTransferFrom(IERC20 token, address from, address to, uint256 value) internal {
          _callOptionalReturn(token, abi.encodeWithSelector(token.transferFrom.selector, from, to, value));
      }
  
      /**
       * @dev Deprecated. This function has issues similar to the ones found in
       * {IERC20-approve}, and its usage is discouraged.
       *
       * Whenever possible, use {safeIncreaseAllowance} and
       * {safeDecreaseAllowance} instead.
       */
      function safeApprove(IERC20 token, address spender, uint256 value) internal {
          // safeApprove should only be called when setting an initial allowance,
          // or when resetting it to zero. To increase and decrease it, use
          // 'safeIncreaseAllowance' and 'safeDecreaseAllowance'
          require(
              (value == 0) || (token.allowance(address(this), spender) == 0),
              "SafeERC20: approve from non-zero to non-zero allowance"
          );
          _callOptionalReturn(token, abi.encodeWithSelector(token.approve.selector, spender, value));
      }
  
      /**
       * @dev Increase the calling contract's allowance toward `spender` by `value`. If `token` returns no value,
       * non-reverting calls are assumed to be successful.
       */
      function safeIncreaseAllowance(IERC20 token, address spender, uint256 value) internal {
          uint256 oldAllowance = token.allowance(address(this), spender);
          _callOptionalReturn(token, abi.encodeWithSelector(token.approve.selector, spender, oldAllowance + value));
      }
  
      /**
       * @dev Decrease the calling contract's allowance toward `spender` by `value`. If `token` returns no value,
       * non-reverting calls are assumed to be successful.
       */
      function safeDecreaseAllowance(IERC20 token, address spender, uint256 value) internal {
          unchecked {
              uint256 oldAllowance = token.allowance(address(this), spender);
              require(oldAllowance >= value, "SafeERC20: decreased allowance below zero");
              _callOptionalReturn(token, abi.encodeWithSelector(token.approve.selector, spender, oldAllowance - value));
          }
      }
  
      /**
       * @dev Set the calling contract's allowance toward `spender` to `value`. If `token` returns no value,
       * non-reverting calls are assumed to be successful. Meant to be used with tokens that require the approval
       * to be set to zero before setting it to a non-zero value, such as USDT.
       */
      function forceApprove(IERC20 token, address spender, uint256 value) internal {
          bytes memory approvalCall = abi.encodeWithSelector(token.approve.selector, spender, value);
  
          if (!_callOptionalReturnBool(token, approvalCall)) {
              _callOptionalReturn(token, abi.encodeWithSelector(token.approve.selector, spender, 0));
              _callOptionalReturn(token, approvalCall);
          }
      }
  
      /**
       * @dev Use a ERC-2612 signature to set the `owner` approval toward `spender` on `token`.
       * Revert on invalid signature.
       */
      function safePermit(
          IERC20Permit token,
          address owner,
          address spender,
          uint256 value,
          uint256 deadline,
          uint8 v,
          bytes32 r,
          bytes32 s
      ) internal {
          uint256 nonceBefore = token.nonces(owner);
          token.permit(owner, spender, value, deadline, v, r, s);
          uint256 nonceAfter = token.nonces(owner);
          require(nonceAfter == nonceBefore + 1, "SafeERC20: permit did not succeed");
      }
  
      /**
       * @dev Imitates a Solidity high-level call (i.e. a regular function call to a contract), relaxing the requirement
       * on the return value: the return value is optional (but if data is returned, it must not be false).
       * @param token The token targeted by the call.
       * @param data The call data (encoded using abi.encode or one of its variants).
       */
      function _callOptionalReturn(IERC20 token, bytes memory data) private {
          // We need to perform a low level call here, to bypass Solidity's return data size checking mechanism, since
          // we're implementing it ourselves. We use {Address-functionCall} to perform this call, which verifies that
          // the target address contains contract code and also asserts for success in the low-level call.
  
          bytes memory returndata = address(token).functionCall(data, "SafeERC20: low-level call failed");
          require(returndata.length == 0 || abi.decode(returndata, (bool)), "SafeERC20: ERC20 operation did not succeed");
      }
  
      /**
       * @dev Imitates a Solidity high-level call (i.e. a regular function call to a contract), relaxing the requirement
       * on the return value: the return value is optional (but if data is returned, it must not be false).
       * @param token The token targeted by the call.
       * @param data The call data (encoded using abi.encode or one of its variants).
       *
       * This is a variant of {_callOptionalReturn} that silents catches all reverts and returns a bool instead.
       */
      function _callOptionalReturnBool(IERC20 token, bytes memory data) private returns (bool) {
          // We need to perform a low level call here, to bypass Solidity's return data size checking mechanism, since
          // we're implementing it ourselves. We cannot use {Address-functionCall} here since this should return false
          // and not revert is the subcall reverts.
  
          (bool success, bytes memory returndata) = address(token).call(data);
          return
              success && (returndata.length == 0 || abi.decode(returndata, (bool))) && Address.isContract(address(token));
      }
  }
  
  
  // File @openzeppelin/contracts/utils/math/Math.sol@v4.9.6
  
  // Original license: SPDX_License_Identifier: MIT
  // OpenZeppelin Contracts (last updated v4.9.0) (utils/math/Math.sol)
  
  pragma solidity ^0.8.0;
  
  /**
   * @dev Standard math utilities missing in the Solidity language.
   */
  library Math {
      enum Rounding {
          Down, // Toward negative infinity
          Up, // Toward infinity
          Zero // Toward zero
      }
  
      /**
       * @dev Returns the largest of two numbers.
       */
      function max(uint256 a, uint256 b) internal pure returns (uint256) {
          return a > b ? a : b;
      }
  
      /**
       * @dev Returns the smallest of two numbers.
       */
      function min(uint256 a, uint256 b) internal pure returns (uint256) {
          return a < b ? a : b;
      }
  
      /**
       * @dev Returns the average of two numbers. The result is rounded towards
       * zero.
       */
      function average(uint256 a, uint256 b) internal pure returns (uint256) {
          // (a + b) / 2 can overflow.
          return (a & b) + (a ^ b) / 2;
      }
  
      /**
       * @dev Returns the ceiling of the division of two numbers.
       *
       * This differs from standard division with `/` in that it rounds up instead
       * of rounding down.
       */
      function ceilDiv(uint256 a, uint256 b) internal pure returns (uint256) {
          // (a + b - 1) / b can overflow on addition, so we distribute.
          return a == 0 ? 0 : (a - 1) / b + 1;
      }
  
      /**
       * @notice Calculates floor(x * y / denominator) with full precision. Throws if result overflows a uint256 or denominator == 0
       * @dev Original credit to Remco Bloemen under MIT license (https://xn--2-umb.com/21/muldiv)
       * with further edits by Uniswap Labs also under MIT license.
       */
      function mulDiv(uint256 x, uint256 y, uint256 denominator) internal pure returns (uint256 result) {
          unchecked {
              // 512-bit multiply [prod1 prod0] = x * y. Compute the product mod 2^256 and mod 2^256 - 1, then use
              // use the Chinese Remainder Theorem to reconstruct the 512 bit result. The result is stored in two 256
              // variables such that product = prod1 * 2^256 + prod0.
              uint256 prod0; // Least significant 256 bits of the product
              uint256 prod1; // Most significant 256 bits of the product
              assembly {
                  let mm := mulmod(x, y, not(0))
                  prod0 := mul(x, y)
                  prod1 := sub(sub(mm, prod0), lt(mm, prod0))
              }
  
              // Handle non-overflow cases, 256 by 256 division.
              if (prod1 == 0) {
                  // Solidity will revert if denominator == 0, unlike the div opcode on its own.
                  // The surrounding unchecked block does not change this fact.
                  // See https://docs.soliditylang.org/en/latest/control-structures.html#checked-or-unchecked-arithmetic.
                  return prod0 / denominator;
              }
  
              // Make sure the result is less than 2^256. Also prevents denominator == 0.
              require(denominator > prod1, "Math: mulDiv overflow");
  
              ///////////////////////////////////////////////
              // 512 by 256 division.
              ///////////////////////////////////////////////
  
              // Make division exact by subtracting the remainder from [prod1 prod0].
              uint256 remainder;
              assembly {
                  // Compute remainder using mulmod.
                  remainder := mulmod(x, y, denominator)
  
                  // Subtract 256 bit number from 512 bit number.
                  prod1 := sub(prod1, gt(remainder, prod0))
                  prod0 := sub(prod0, remainder)
              }
  
              // Factor powers of two out of denominator and compute largest power of two divisor of denominator. Always >= 1.
              // See https://cs.stackexchange.com/q/138556/92363.
  
              // Does not overflow because the denominator cannot be zero at this stage in the function.
              uint256 twos = denominator & (~denominator + 1);
              assembly {
                  // Divide denominator by twos.
                  denominator := div(denominator, twos)
  
                  // Divide [prod1 prod0] by twos.
                  prod0 := div(prod0, twos)
  
                  // Flip twos such that it is 2^256 / twos. If twos is zero, then it becomes one.
                  twos := add(div(sub(0, twos), twos), 1)
              }
  
              // Shift in bits from prod1 into prod0.
              prod0 |= prod1 * twos;
  
              // Invert denominator mod 2^256. Now that denominator is an odd number, it has an inverse modulo 2^256 such
              // that denominator * inv = 1 mod 2^256. Compute the inverse by starting with a seed that is correct for
              // four bits. That is, denominator * inv = 1 mod 2^4.
              uint256 inverse = (3 * denominator) ^ 2;
  
              // Use the Newton-Raphson iteration to improve the precision. Thanks to Hensel's lifting lemma, this also works
              // in modular arithmetic, doubling the correct bits in each step.
              inverse *= 2 - denominator * inverse; // inverse mod 2^8
              inverse *= 2 - denominator * inverse; // inverse mod 2^16
              inverse *= 2 - denominator * inverse; // inverse mod 2^32
              inverse *= 2 - denominator * inverse; // inverse mod 2^64
              inverse *= 2 - denominator * inverse; // inverse mod 2^128
              inverse *= 2 - denominator * inverse; // inverse mod 2^256
  
              // Because the division is now exact we can divide by multiplying with the modular inverse of denominator.
              // This will give us the correct result modulo 2^256. Since the preconditions guarantee that the outcome is
              // less than 2^256, this is the final result. We don't need to compute the high bits of the result and prod1
              // is no longer required.
              result = prod0 * inverse;
              return result;
          }
      }
  
      /**
       * @notice Calculates x * y / denominator with full precision, following the selected rounding direction.
       */
      function mulDiv(uint256 x, uint256 y, uint256 denominator, Rounding rounding) internal pure returns (uint256) {
          uint256 result = mulDiv(x, y, denominator);
          if (rounding == Rounding.Up && mulmod(x, y, denominator) > 0) {
              result += 1;
          }
          return result;
      }
  
      /**
       * @dev Returns the square root of a number. If the number is not a perfect square, the value is rounded down.
       *
       * Inspired by Henry S. Warren, Jr.'s "Hacker's Delight" (Chapter 11).
       */
      function sqrt(uint256 a) internal pure returns (uint256) {
          if (a == 0) {
              return 0;
          }
  
          // For our first guess, we get the biggest power of 2 which is smaller than the square root of the target.
          //
          // We know that the "msb" (most significant bit) of our target number `a` is a power of 2 such that we have
          // `msb(a) <= a < 2*msb(a)`. This value can be written `msb(a)=2**k` with `k=log2(a)`.
          //
          // This can be rewritten `2**log2(a) <= a < 2**(log2(a) + 1)`
          // → `sqrt(2**k) <= sqrt(a) < sqrt(2**(k+1))`
          // → `2**(k/2) <= sqrt(a) < 2**((k+1)/2) <= 2**(k/2 + 1)`
          //
          // Consequently, `2**(log2(a) / 2)` is a good first approximation of `sqrt(a)` with at least 1 correct bit.
          uint256 result = 1 << (log2(a) >> 1);
  
          // At this point `result` is an estimation with one bit of precision. We know the true value is a uint128,
          // since it is the square root of a uint256. Newton's method converges quadratically (precision doubles at
          // every iteration). We thus need at most 7 iteration to turn our partial result with one bit of precision
          // into the expected uint128 result.
          unchecked {
              result = (result + a / result) >> 1;
              result = (result + a / result) >> 1;
              result = (result + a / result) >> 1;
              result = (result + a / result) >> 1;
              result = (result + a / result) >> 1;
              result = (result + a / result) >> 1;
              result = (result + a / result) >> 1;
              return min(result, a / result);
          }
      }
  
      /**
       * @notice Calculates sqrt(a), following the selected rounding direction.
       */
      function sqrt(uint256 a, Rounding rounding) internal pure returns (uint256) {
          unchecked {
              uint256 result = sqrt(a);
              return result + (rounding == Rounding.Up && result * result < a ? 1 : 0);
          }
      }
  
      /**
       * @dev Return the log in base 2, rounded down, of a positive value.
       * Returns 0 if given 0.
       */
      function log2(uint256 value) internal pure returns (uint256) {
          uint256 result = 0;
          unchecked {
              if (value >> 128 > 0) {
                  value >>= 128;
                  result += 128;
              }
              if (value >> 64 > 0) {
                  value >>= 64;
                  result += 64;
              }
              if (value >> 32 > 0) {
                  value >>= 32;
                  result += 32;
              }
              if (value >> 16 > 0) {
                  value >>= 16;
                  result += 16;
              }
              if (value >> 8 > 0) {
                  value >>= 8;
                  result += 8;
              }
              if (value >> 4 > 0) {
                  value >>= 4;
                  result += 4;
              }
              if (value >> 2 > 0) {
                  value >>= 2;
                  result += 2;
              }
              if (value >> 1 > 0) {
                  result += 1;
              }
          }
          return result;
      }
  
      /**
       * @dev Return the log in base 2, following the selected rounding direction, of a positive value.
       * Returns 0 if given 0.
       */
      function log2(uint256 value, Rounding rounding) internal pure returns (uint256) {
          unchecked {
              uint256 result = log2(value);
              return result + (rounding == Rounding.Up && 1 << result < value ? 1 : 0);
          }
      }
  
      /**
       * @dev Return the log in base 10, rounded down, of a positive value.
       * Returns 0 if given 0.
       */
      function log10(uint256 value) internal pure returns (uint256) {
          uint256 result = 0;
          unchecked {
              if (value >= 10 ** 64) {
                  value /= 10 ** 64;
                  result += 64;
              }
              if (value >= 10 ** 32) {
                  value /= 10 ** 32;
                  result += 32;
              }
              if (value >= 10 ** 16) {
                  value /= 10 ** 16;
                  result += 16;
              }
              if (value >= 10 ** 8) {
                  value /= 10 ** 8;
                  result += 8;
              }
              if (value >= 10 ** 4) {
                  value /= 10 ** 4;
                  result += 4;
              }
              if (value >= 10 ** 2) {
                  value /= 10 ** 2;
                  result += 2;
              }
              if (value >= 10 ** 1) {
                  result += 1;
              }
          }
          return result;
      }
  
      /**
       * @dev Return the log in base 10, following the selected rounding direction, of a positive value.
       * Returns 0 if given 0.
       */
      function log10(uint256 value, Rounding rounding) internal pure returns (uint256) {
          unchecked {
              uint256 result = log10(value);
              return result + (rounding == Rounding.Up && 10 ** result < value ? 1 : 0);
          }
      }
  
      /**
       * @dev Return the log in base 256, rounded down, of a positive value.
       * Returns 0 if given 0.
       *
       * Adding one to the result gives the number of pairs of hex symbols needed to represent `value` as a hex string.
       */
      function log256(uint256 value) internal pure returns (uint256) {
          uint256 result = 0;
          unchecked {
              if (value >> 128 > 0) {
                  value >>= 128;
                  result += 16;
              }
              if (value >> 64 > 0) {
                  value >>= 64;
                  result += 8;
              }
              if (value >> 32 > 0) {
                  value >>= 32;
                  result += 4;
              }
              if (value >> 16 > 0) {
                  value >>= 16;
                  result += 2;
              }
              if (value >> 8 > 0) {
                  result += 1;
              }
          }
          return result;
      }
  
      /**
       * @dev Return the log in base 256, following the selected rounding direction, of a positive value.
       * Returns 0 if given 0.
       */
      function log256(uint256 value, Rounding rounding) internal pure returns (uint256) {
          unchecked {
              uint256 result = log256(value);
              return result + (rounding == Rounding.Up && 1 << (result << 3) < value ? 1 : 0);
          }
      }
  }
  
  
  // File @openzeppelin/contracts/token/ERC20/extensions/ERC4626.sol@v4.9.6
  
  // Original license: SPDX_License_Identifier: MIT
  // OpenZeppelin Contracts (last updated v4.9.0) (token/ERC20/extensions/ERC4626.sol)
  
  pragma solidity ^0.8.0;
  
  
  
  
  /**
   * @dev Implementation of the ERC4626 "Tokenized Vault Standard" as defined in
   * https://eips.ethereum.org/EIPS/eip-4626[EIP-4626].
   *
   * This extension allows the minting and burning of "shares" (represented using the ERC20 inheritance) in exchange for
   * underlying "assets" through standardized {deposit}, {mint}, {redeem} and {burn} workflows. This contract extends
   * the ERC20 standard. Any additional extensions included along it would affect the "shares" token represented by this
   * contract and not the "assets" token which is an independent contract.
   *
   * [CAUTION]
   * ====
   * In empty (or nearly empty) ERC-4626 vaults, deposits are at high risk of being stolen through frontrunning
   * with a "donation" to the vault that inflates the price of a share. This is variously known as a donation or inflation
   * attack and is essentially a problem of slippage. Vault deployers can protect against this attack by making an initial
   * deposit of a non-trivial amount of the asset, such that price manipulation becomes infeasible. Withdrawals may
   * similarly be affected by slippage. Users can protect against this attack as well as unexpected slippage in general by
   * verifying the amount received is as expected, using a wrapper that performs these checks such as
   * https://github.com/fei-protocol/ERC4626#erc4626router-and-base[ERC4626Router].
   *
   * Since v4.9, this implementation uses virtual assets and shares to mitigate that risk. The `_decimalsOffset()`
   * corresponds to an offset in the decimal representation between the underlying asset's decimals and the vault
   * decimals. This offset also determines the rate of virtual shares to virtual assets in the vault, which itself
   * determines the initial exchange rate. While not fully preventing the attack, analysis shows that the default offset
   * (0) makes it non-profitable, as a result of the value being captured by the virtual shares (out of the attacker's
   * donation) matching the attacker's expected gains. With a larger offset, the attack becomes orders of magnitude more
   * expensive than it is profitable. More details about the underlying math can be found
   * xref:erc4626.adoc#inflation-attack[here].
   *
   * The drawback of this approach is that the virtual shares do capture (a very small) part of the value being accrued
   * to the vault. Also, if the vault experiences losses, the users try to exit the vault, the virtual shares and assets
   * will cause the first user to exit to experience reduced losses in detriment to the last users that will experience
   * bigger losses. Developers willing to revert back to the pre-v4.9 behavior just need to override the
   * `_convertToShares` and `_convertToAssets` functions.
   *
   * To learn more, check out our xref:ROOT:erc4626.adoc[ERC-4626 guide].
   * ====
   *
   * _Available since v4.7._
   */
  abstract contract ERC4626 is ERC20, IERC4626 {
      using Math for uint256;
  
      IERC20 private immutable _asset;
      uint8 private immutable _underlyingDecimals;
  
      /**
       * @dev Set the underlying asset contract. This must be an ERC20-compatible contract (ERC20 or ERC777).
       */
      constructor(IERC20 asset_) {
          (bool success, uint8 assetDecimals) = _tryGetAssetDecimals(asset_);
          _underlyingDecimals = success ? assetDecimals : 18;
          _asset = asset_;
      }
  
      /**
       * @dev Attempts to fetch the asset decimals. A return value of false indicates that the attempt failed in some way.
       */
      function _tryGetAssetDecimals(IERC20 asset_) private view returns (bool, uint8) {
          (bool success, bytes memory encodedDecimals) = address(asset_).staticcall(
              abi.encodeWithSelector(IERC20Metadata.decimals.selector)
          );
          if (success && encodedDecimals.length >= 32) {
              uint256 returnedDecimals = abi.decode(encodedDecimals, (uint256));
              if (returnedDecimals <= type(uint8).max) {
                  return (true, uint8(returnedDecimals));
              }
          }
          return (false, 0);
      }
  
      /**
       * @dev Decimals are computed by adding the decimal offset on top of the underlying asset's decimals. This
       * "original" value is cached during construction of the vault contract. If this read operation fails (e.g., the
       * asset has not been created yet), a default of 18 is used to represent the underlying asset's decimals.
       *
       * See {IERC20Metadata-decimals}.
       */
      function decimals() public view virtual override(IERC20Metadata, ERC20) returns (uint8) {
          return _underlyingDecimals + _decimalsOffset();
      }
  
      /** @dev See {IERC4626-asset}. */
      function asset() public view virtual override returns (address) {
          return address(_asset);
      }
  
      /** @dev See {IERC4626-totalAssets}. */
      function totalAssets() public view virtual override returns (uint256) {
          return _asset.balanceOf(address(this));
      }
  
      /** @dev See {IERC4626-convertToShares}. */
      function convertToShares(uint256 assets) public view virtual override returns (uint256) {
          return _convertToShares(assets, Math.Rounding.Down);
      }
  
      /** @dev See {IERC4626-convertToAssets}. */
      function convertToAssets(uint256 shares) public view virtual override returns (uint256) {
          return _convertToAssets(shares, Math.Rounding.Down);
      }
  
      /** @dev See {IERC4626-maxDeposit}. */
      function maxDeposit(address) public view virtual override returns (uint256) {
          return type(uint256).max;
      }
  
      /** @dev See {IERC4626-maxMint}. */
      function maxMint(address) public view virtual override returns (uint256) {
          return type(uint256).max;
      }
  
      /** @dev See {IERC4626-maxWithdraw}. */
      function maxWithdraw(address owner) public view virtual override returns (uint256) {
          return _convertToAssets(balanceOf(owner), Math.Rounding.Down);
      }
  
      /** @dev See {IERC4626-maxRedeem}. */
      function maxRedeem(address owner) public view virtual override returns (uint256) {
          return balanceOf(owner);
      }
  
      /** @dev See {IERC4626-previewDeposit}. */
      function previewDeposit(uint256 assets) public view virtual override returns (uint256) {
          return _convertToShares(assets, Math.Rounding.Down);
      }
  
      /** @dev See {IERC4626-previewMint}. */
      function previewMint(uint256 shares) public view virtual override returns (uint256) {
          return _convertToAssets(shares, Math.Rounding.Up);
      }
  
      /** @dev See {IERC4626-previewWithdraw}. */
      function previewWithdraw(uint256 assets) public view virtual override returns (uint256) {
          return _convertToShares(assets, Math.Rounding.Up);
      }
  
      /** @dev See {IERC4626-previewRedeem}. */
      function previewRedeem(uint256 shares) public view virtual override returns (uint256) {
          return _convertToAssets(shares, Math.Rounding.Down);
      }
  
      /** @dev See {IERC4626-deposit}. */
      function deposit(uint256 assets, address receiver) public virtual override returns (uint256) {
          require(assets <= maxDeposit(receiver), "ERC4626: deposit more than max");
  
          uint256 shares = previewDeposit(assets);
          _deposit(_msgSender(), receiver, assets, shares);
  
          return shares;
      }
  
      /** @dev See {IERC4626-mint}.
       *
       * As opposed to {deposit}, minting is allowed even if the vault is in a state where the price of a share is zero.
       * In this case, the shares will be minted without requiring any assets to be deposited.
       */
      function mint(uint256 shares, address receiver) public virtual override returns (uint256) {
          require(shares <= maxMint(receiver), "ERC4626: mint more than max");
  
          uint256 assets = previewMint(shares);
          _deposit(_msgSender(), receiver, assets, shares);
  
          return assets;
      }
  
      /** @dev See {IERC4626-withdraw}. */
      function withdraw(uint256 assets, address receiver, address owner) public virtual override returns (uint256) {
          require(assets <= maxWithdraw(owner), "ERC4626: withdraw more than max");
  
          uint256 shares = previewWithdraw(assets);
          _withdraw(_msgSender(), receiver, owner, assets, shares);
  
          return shares;
      }
  
      /** @dev See {IERC4626-redeem}. */
      function redeem(uint256 shares, address receiver, address owner) public virtual override returns (uint256) {
          require(shares <= maxRedeem(owner), "ERC4626: redeem more than max");
  
          uint256 assets = previewRedeem(shares);
          _withdraw(_msgSender(), receiver, owner, assets, shares);
  
          return assets;
      }
  
      /**
       * @dev Internal conversion function (from assets to shares) with support for rounding direction.
       */
      function _convertToShares(uint256 assets, Math.Rounding rounding) internal view virtual returns (uint256) {
          return assets.mulDiv(totalSupply() + 10 ** _decimalsOffset(), totalAssets() + 1, rounding);
      }
  
      /**
       * @dev Internal conversion function (from shares to assets) with support for rounding direction.
       */
      function _convertToAssets(uint256 shares, Math.Rounding rounding) internal view virtual returns (uint256) {
          return shares.mulDiv(totalAssets() + 1, totalSupply() + 10 ** _decimalsOffset(), rounding);
      }
  
      /**
       * @dev Deposit/mint common workflow.
       */
      function _deposit(address caller, address receiver, uint256 assets, uint256 shares) internal virtual {
          // If _asset is ERC777, `transferFrom` can trigger a reentrancy BEFORE the transfer happens through the
          // `tokensToSend` hook. On the other hand, the `tokenReceived` hook, that is triggered after the transfer,
          // calls the vault, which is assumed not malicious.
          //
          // Conclusion: we need to do the transfer before we mint so that any reentrancy would happen before the
          // assets are transferred and before the shares are minted, which is a valid state.
          // slither-disable-next-line reentrancy-no-eth
          SafeERC20.safeTransferFrom(_asset, caller, address(this), assets);
          _mint(receiver, shares);
  
          emit Deposit(caller, receiver, assets, shares);
      }
  
      /**
       * @dev Withdraw/redeem common workflow.
       */
      function _withdraw(
          address caller,
          address receiver,
          address owner,
          uint256 assets,
          uint256 shares
      ) internal virtual {
          if (caller != owner) {
              _spendAllowance(owner, caller, shares);
          }
  
          // If _asset is ERC777, `transfer` can trigger a reentrancy AFTER the transfer happens through the
          // `tokensReceived` hook. On the other hand, the `tokensToSend` hook, that is triggered before the transfer,
          // calls the vault, which is assumed not malicious.
          //
          // Conclusion: we need to do the transfer after the burn so that any reentrancy would happen after the
          // shares are burned and after the assets are transferred, which is a valid state.
          _burn(owner, shares);
          SafeERC20.safeTransfer(_asset, receiver, assets);
  
          emit Withdraw(caller, receiver, owner, assets, shares);
      }
  
      function _decimalsOffset() internal view virtual returns (uint8) {
          return 0;
      }
  }
  
  
  // File src/intf/IImpactVault.sol
  
  // Original license: SPDX_License_Identifier: MIT
  pragma solidity 0.8.19;
  
  //    █████████   ███████████     █████████   ███████████     ███████████    █████████   ██████   █████ █████   ████     █████████  █████   ███   █████ █████ ███████████ ███████████ ██████████ ███████████   █████         █████████   ██████   █████ ██████████
  //   ███░░░░░███ ░░███░░░░░███   ███░░░░░███ ░░███░░░░░███   ░░███░░░░░███  ███░░░░░███ ░░██████ ░░███ ░░███   ███░     ███░░░░░███░░███   ░███  ░░███ ░░███ ░█░░░███░░░█░█░░░░░░███ ░░███░░░░░█░░███░░░░░███ ░░███         ███░░░░░███ ░░██████ ░░███ ░░███░░░░███
  //  ░███    ░███  ░███    ░███  ░███    ░███  ░███    ░███    ░███    ░███ ░███    ░███  ░███░███ ░███  ░███  ███      ░███    ░░░  ░███   ░███   ░███  ░███ ░   ░███  ░ ░     ███░   ░███  █ ░  ░███    ░███  ░███        ░███    ░███  ░███░███ ░███  ░███   ░░███
  //  ░███████████  ░██████████   ░███████████  ░██████████     ░██████████  ░███████████  ░███░░███░███  ░███████       ░░█████████  ░███   ░███   ░███  ░███     ░███         ███     ░██████    ░██████████   ░███        ░███████████  ░███░░███░███  ░███    ░███
  //  ░███░░░░░███  ░███░░░░░███  ░███░░░░░███  ░███░░░░░███    ░███░░░░░███ ░███░░░░░███  ░███ ░░██████  ░███░░███       ░░░░░░░░███ ░░███  █████  ███   ░███     ░███        ███      ░███░░█    ░███░░░░░███  ░███        ░███░░░░░███  ░███ ░░██████  ░███    ░███
  //  ░███    ░███  ░███    ░███  ░███    ░███  ░███    ░███    ░███    ░███ ░███    ░███  ░███  ░░█████  ░███ ░░███      ███    ░███  ░░░█████░█████░    ░███     ░███      ████     █ ░███ ░   █ ░███    ░███  ░███      █ ░███    ░███  ░███  ░░█████  ░███    ███
  //  █████   █████ █████   █████ █████   █████ ███████████     ███████████  █████   █████ █████  ░░█████ █████ ░░████   ░░█████████     ░░███ ░░███      █████    █████    ███████████ ██████████ █████   █████ ███████████ █████   █████ █████  ░░█████ ██████████
  // ░░░░░   ░░░░░ ░░░░░   ░░░░░ ░░░░░   ░░░░░ ░░░░░░░░░░░     ░░░░░░░░░░░  ░░░░░   ░░░░░ ░░░░░    ░░░░░ ░░░░░   ░░░░     ░░░░░░░░░       ░░░   ░░░      ░░░░░    ░░░░░    ░░░░░░░░░░░ ░░░░░░░░░░ ░░░░░   ░░░░░ ░░░░░░░░░░░ ░░░░░   ░░░░░ ░░░░░    ░░░░░ ░░░░░░░░░░
  //
  //
  //    ,ad8888ba,         db         88888888ba,    88b           d88    ,ad8888ba,     ad88888ba
  //   d8"'    `"8b       d88b        88      `"8b   888b         d888   d8"'    `"8b   d8"     "8b
  //  d8'                d8'`8b       88        `8b  88`8b       d8'88  d8'        `8b  Y8,
  //  88                d8'  `8b      88         88  88 `8b     d8' 88  88          88  `Y8aaaaa,
  //  88               d8YaaaaY8b     88         88  88  `8b   d8'  88  88          88    `"""""8b,
  //  Y8,             d8""""""""8b    88         8P  88   `8b d8'   88  Y8,        ,8P          `8b
  //   Y8a.    .a8P  d8'        `8b   88      .a8P   88    `888'    88   Y8a.    .a8P   Y8a     a8P
  //    `"Y8888Y"'  d8'          `8b  88888888Y"'    88     `8'     88    `"Y8888Y"'     "Y88888P"
  //
  // ===============================================================================================
  // =====================================  IImpactVault  ==========================================
  // ===============================================================================================
  // ARAB BANK SWITZZERLAND: https://github.com/ArabBankSwitzerland
  // CADMOS: https://github.com/Cadmos-finance
  
  // Primary Author(s)
  // N.B.: https://github.com/nboueri
  // J.A.T: https://github.com/jat9292
  /// @title Interface of the ImpactVault Contract
  /// @author N.B.
  /// @notice Used to donate gains stemming from a positively rebasing token
  interface IImpactVault is IERC20Metadata {
  
      error DepositTooLow();
  
      struct TimelockedSurplus {
          uint128 surplus; // TimeLocked surplus - distributable at timelock expiry (1 day)
          uint64 timestamp; // Ok until 2554  - timestamp when surplus was timelocked
          uint64 minimalCollectAmount; // Minimal Amount to auto-Collect at each deposit/ withdrawal - can be set by _owner
      }
  
      /* ========== MUTATIVE FUNCTIONS ========== */
  
      /// @notice Collects Asset Surplus as a donation for Owner - Does not collect if surplus is less than minimalTransfer
      function collectDonations(
          uint64 minimalTransfer
      )
          external
          returns (
              uint128 collectedAmount,
              uint256 netWealth,
              uint256 totalSupply
          );
  
      /* ========== RESTRICTED FUNCTIONS ========== */
  
      /// @notice Allows Owner to set minimalCollectAmount
      function setAutoCollectThreshold(uint64 newMinimalCollectAmount) external;
  
      /* ========== EVENTS ========== */
  
      event SetAutoCollectThreshold(
          uint64 newMinimalCollectAmount,
          uint64 oldMinimalCollectAmount
      );
  }
  
  
  // File src/ImpactVault.sol
  
  // Original license: SPDX_License_Identifier: MIT
  pragma solidity 0.8.19;
  
  
  
  //    █████████   ███████████     █████████   ███████████     ███████████    █████████   ██████   █████ █████   ████     █████████  █████   ███   █████ █████ ███████████ ███████████ ██████████ ███████████   █████         █████████   ██████   █████ ██████████
  //   ███░░░░░███ ░░███░░░░░███   ███░░░░░███ ░░███░░░░░███   ░░███░░░░░███  ███░░░░░███ ░░██████ ░░███ ░░███   ███░     ███░░░░░███░░███   ░███  ░░███ ░░███ ░█░░░███░░░█░█░░░░░░███ ░░███░░░░░█░░███░░░░░███ ░░███         ███░░░░░███ ░░██████ ░░███ ░░███░░░░███
  //  ░███    ░███  ░███    ░███  ░███    ░███  ░███    ░███    ░███    ░███ ░███    ░███  ░███░███ ░███  ░███  ███      ░███    ░░░  ░███   ░███   ░███  ░███ ░   ░███  ░ ░     ███░   ░███  █ ░  ░███    ░███  ░███        ░███    ░███  ░███░███ ░███  ░███   ░░███
  //  ░███████████  ░██████████   ░███████████  ░██████████     ░██████████  ░███████████  ░███░░███░███  ░███████       ░░█████████  ░███   ░███   ░███  ░███     ░███         ███     ░██████    ░██████████   ░███        ░███████████  ░███░░███░███  ░███    ░███
  //  ░███░░░░░███  ░███░░░░░███  ░███░░░░░███  ░███░░░░░███    ░███░░░░░███ ░███░░░░░███  ░███ ░░██████  ░███░░███       ░░░░░░░░███ ░░███  █████  ███   ░███     ░███        ███      ░███░░█    ░███░░░░░███  ░███        ░███░░░░░███  ░███ ░░██████  ░███    ░███
  //  ░███    ░███  ░███    ░███  ░███    ░███  ░███    ░███    ░███    ░███ ░███    ░███  ░███  ░░█████  ░███ ░░███      ███    ░███  ░░░█████░█████░    ░███     ░███      ████     █ ░███ ░   █ ░███    ░███  ░███      █ ░███    ░███  ░███  ░░█████  ░███    ███
  //  █████   █████ █████   █████ █████   █████ ███████████     ███████████  █████   █████ █████  ░░█████ █████ ░░████   ░░█████████     ░░███ ░░███      █████    █████    ███████████ ██████████ █████   █████ ███████████ █████   █████ █████  ░░█████ ██████████
  // ░░░░░   ░░░░░ ░░░░░   ░░░░░ ░░░░░   ░░░░░ ░░░░░░░░░░░     ░░░░░░░░░░░  ░░░░░   ░░░░░ ░░░░░    ░░░░░ ░░░░░   ░░░░     ░░░░░░░░░       ░░░   ░░░      ░░░░░    ░░░░░    ░░░░░░░░░░░ ░░░░░░░░░░ ░░░░░   ░░░░░ ░░░░░░░░░░░ ░░░░░   ░░░░░ ░░░░░    ░░░░░ ░░░░░░░░░░
  //
  //
  //    ,ad8888ba,         db         88888888ba,    88b           d88    ,ad8888ba,     ad88888ba
  //   d8"'    `"8b       d88b        88      `"8b   888b         d888   d8"'    `"8b   d8"     "8b
  //  d8'                d8'`8b       88        `8b  88`8b       d8'88  d8'        `8b  Y8,
  //  88                d8'  `8b      88         88  88 `8b     d8' 88  88          88  `Y8aaaaa,
  //  88               d8YaaaaY8b     88         88  88  `8b   d8'  88  88          88    `"""""8b,
  //  Y8,             d8""""""""8b    88         8P  88   `8b d8'   88  Y8,        ,8P          `8b
  //   Y8a.    .a8P  d8'        `8b   88      .a8P   88    `888'    88   Y8a.    .a8P   Y8a     a8P
  //    `"Y8888Y"'  d8'          `8b  88888888Y"'    88     `8'     88    `"Y8888Y"'     "Y88888P"
  //
  // ===============================================================================================
  // ======================================  ImpactVault  =========================================
  // ===============================================================================================
  // ARAB BANK SWITZZERLAND: https://github.com/ArabBankSwitzerland
  // CADMOS: https://github.com/Cadmos-finance
  
  // Primary Author(s)
  // N.B.: https://github.com/nboueri
  // J.A.T: https://github.com/jat9292
  /// @title Impact Vault Smart Contract
  /// @author N.B.
  /// @notice Used to donate gains stemming from a positively rebasing token
  contract ImpactVault is ERC4626, Ownable2Step, IImpactVault {
      using SafeERC20 for IERC20;
      using Math for uint256;
  
      /* ========== CONSTANTS ========== */
  
      uint256 internal immutable MIN_DEPOSIT;
  
      /* ========== STATE VARIABLES ========== */
  
      /*
      struct TimelockedSurplus {
          uint128 surplus; // TimeLocked surplus - distributable at timelock expiry (3 day)
          uint64 timestamp; // Ok until year 2554  - timestamp when surplus was timelocked
          uint64 minimalCollectAmount; // Minimal Amount to auto-Collect at each deposit/ withdrawal - can be set by _owner. uint64 -> ~ 18 wad
      }
      */
      TimelockedSurplus public timeLockedSurplus;
  
      /* ========== CONSTRUCTOR ========== */
  
      /**
       * @dev Assumptions: Asset is a positively increasing rebasing token (e.g: STETH), all gains are distributed to _owner.
       * In case of slashing, we wait for the asset to rebase > 1 before resuming distributions.
       * To alleviate risk if Asset rebases Up then Down (e.g. StETH: 1 - > 1.30 -> 1.0) due for instance to an operational blunder of asset issuer, we have put in place a 24-hour timelock before surplus distribution takes place.
       * minDeposit param sets minimal deposit size in asset, for StEth which has a few wei imprecision in transfer, we use 1Gwei
       * @dev On deployment it is recommended to make a donation of MIN_DEPOSIT to the vault to prevent potential rounding issues in the future
       */
      constructor(
          IERC20 asset_,
          string memory name,
          string memory symbol,
          uint256 minDeposit
      ) ERC20(name, symbol) ERC4626(asset_) {
          MIN_DEPOSIT = minDeposit;
      }
  
      /* ========== INTERNAL FUNCTIONS ========== */
  
      /**
       * @dev Internal conversion function (from assets to shares) with support for rounding direction.
       */
      function _convertToSharesCompute(
          uint256 assets,
          Math.Rounding rounding,
          uint256 totalAssets_,
          uint256 totalSupply_
      ) internal pure returns (uint256) {
          if (totalAssets_ < totalSupply_) {
              // if 1 Vault Share is worth less than 1 asset, obtain more shares pro-rata the vault NAV. Necessary to ensure no loss on withdrawal
              return assets.mulDiv(totalSupply_ + 1, totalAssets_ + 1, rounding);
          }
          return assets; //Else 1 deposited asset = 1 share
      }
  
      /**
       * @dev Internal conversion function (from assets to shares) with support for rounding direction.
       */
      function _convertToAssetsCompute(
          uint256 shares,
          Math.Rounding rounding,
          uint256 totalAssets_,
          uint256 totalSupply_
      ) internal pure returns (uint256) {
          if (totalAssets_ < totalSupply_) {
              // if 1 Vault Share is worth less than 1 asset, obtain more shares pro-rata the vault NAV. Necessary to ensure no loss on withdrawal
              return shares.mulDiv(totalAssets_ + 1, totalSupply_ + 1, rounding);
          }
          return shares; //Else 1 deposited asset = 1 share
      }
  
      /**
       * @dev Internal conversion function (from assets to shares) with support for rounding direction.
       */
      function _convertToShares(
          uint256 assets,
          Math.Rounding rounding
      ) internal view override(ERC4626) returns (uint256) {
          uint256 totalAssets_ = totalAssets();
          uint256 totalSupply_ = totalSupply();
          return
              _convertToSharesCompute(
                  assets,
                  rounding,
                  totalAssets_,
                  totalSupply_
              );
      }
  
      /**
       * @dev Internal conversion function (from shares to assets) with support for rounding direction.
       */
      function _convertToAssets(
          uint256 shares,
          Math.Rounding rounding
      ) internal view override(ERC4626) returns (uint256) {
          uint256 totalAssets_ = totalAssets();
          uint256 totalSupply_ = totalSupply();
          return
              _convertToAssetsCompute(
                  shares,
                  rounding,
                  totalAssets_,
                  totalSupply_
              );
      }
  
      /// @dev Calls CollectDonations and returns result of _convertToShares
      function _collectDonationsAndConvertToShares(
          uint256 assets,
          Math.Rounding rounding
      ) internal returns (uint256) {
          (, uint256 totalAssets_, uint256 totalSupply_) = collectDonations(0);
          return
              _convertToSharesCompute(
                  assets,
                  rounding,
                  totalAssets_,
                  totalSupply_
              );
      }
  
      /// @dev Calls CollectDonations and returns result of _convertToAssets
      function _collectDonationsAndConvertToAssets(
          uint256 shares,
          Math.Rounding rounding
      ) internal returns (uint256) {
          (, uint256 totalAssets_, uint256 totalSupply_) = collectDonations(0);
          return
              _convertToAssetsCompute(
                  shares,
                  rounding,
                  totalAssets_,
                  totalSupply_
              );
      }
  
      /* ========== MUTATIVE FUNCTIONS ========== */
  
      /** @dev See {IERC4626-deposit}. */
      /// @notice  Deposit amount from msg.sender of asset into the vault and sends obtained tokens to receiver
      /// @notice Due to stETH internal mechanics, user may deposit one or two wei less than expected; see https://docs.lido.fi/guides/lido-tokens-integration-guide#1-2-wei-corner-case
      /// @dev normally asset is positively rebasing and we obtain 1 vault share per deposited asset, we however adjust the price if there was an adverse rebasing
      /// @param assets Amount of Asset to Deposit
      /// @param receiver Address receiving freshly minted vault tokens
      function deposit(
          uint256 assets,
          address receiver
      ) public override(ERC4626) returns (uint256) {
          uint256 shares = _collectDonationsAndConvertToShares(
              assets,
              Math.Rounding.Down
          );
          if (assets <= MIN_DEPOSIT){
              revert DepositTooLow();
          }
          _deposit(_msgSender(), receiver, assets, shares);
          return shares;
      }
  
      /** @dev See {IERC4626-mint}. */
      /// @notice  Mint shares to receiver against assets from msg.sender
      /// @notice Due to stETH internal mechanics, user may deposit one or two wei less than expected; see https://docs.lido.fi/guides/lido-tokens-integration-guide#1-2-wei-corner-case
      /// @dev normally asset is positively rebasing and we obtain 1 vault share per deposited asset, we however adjust the price if there was an adverse rebasing
      /// @param shares Amount of Shares to obtain
      /// @param receiver Address receiving freshly minted vault tokens
      function mint(
          uint256 shares,
          address receiver
      ) public override(ERC4626) returns (uint256) {
          uint256 assets = _collectDonationsAndConvertToAssets(
              shares,
              Math.Rounding.Up
          );
          if (assets <= MIN_DEPOSIT){
              revert DepositTooLow();
          }
          _deposit(_msgSender(), receiver, assets, shares);
          return assets;
      }
  
      /** @dev See {IERC4626-withdraw}. */
      /// @notice Withdraws assets to receiver address against owner vault shares
      /// @notice Due to stETH internal mechanics, user may receive one or two wei less than expected; see https://docs.lido.fi/guides/lido-tokens-integration-guide#1-2-wei-corner-case
      /// @dev normally asset is positively rebasing and we obtain 1 asset per canceled vault share, we however adjust the price if there was an adverse rebasing
      /// @param assets Amount of Assets to obtain
      /// @param receiver Address receiving the withdrawn assets
      /// @param owner Address owning the vault shares to burn
      function withdraw(
          uint256 assets,
          address receiver,
          address owner
      ) public override(ERC4626) returns (uint256) {
          uint256 shares = _collectDonationsAndConvertToShares(
              assets,
              Math.Rounding.Up
          );
          _withdraw(_msgSender(), receiver, owner, assets, shares);
          return shares;
      }
  
      /** @dev See {IERC4626-redeem}. */
      /// @notice Cancels amount shares of msg.sender and withdraws asset
      /// @notice Due to stETH internal mechanics, user may receive one or two wei less than expected; see https://docs.lido.fi/guides/lido-tokens-integration-guide#1-2-wei-corner-case
      /// @dev normally asset is positively rebasing and we obtain 1 asset per canceled vault share, we however adjust the price if there was an adverse rebasing
      /// @param shares Amount of Vault Shares to Cancel
      /// @param receiver Address receiving the withdrawn assets
      /// @param owner Address owning the vault shares to burn
      function redeem(
          uint256 shares,
          address receiver,
          address owner
      ) public override(ERC4626) returns (uint256) {
          uint256 assets = _collectDonationsAndConvertToAssets(
              shares,
              Math.Rounding.Down
          );
          _withdraw(_msgSender(), receiver, owner, assets, shares);
          return assets;
      }
  
      /// @notice Collects Asset Surplus as a donation for Owner
      /// @dev Does not collect if 24-hour timeLocked surplus is less than minimalTransfer
      /// @dev At most collects Once a day
      /// @dev caller indicates minimalTransferAmount for computation to take place - if 0 is indicated we revert to default minimum (as registered in storage)
      function collectDonations(
          uint64 minimalTransfer
      )
          public
          override(IImpactVault)
          returns (
              uint128 collectedAmount,
              uint256 totalAssets_,
              uint256 totalSupply_
          )
      {
          totalSupply_ = totalSupply();
          totalAssets_ = totalAssets();
          TimelockedSurplus memory timeLockedSurplus_ = timeLockedSurplus;
          minimalTransfer = minimalTransfer == 0
              ? timeLockedSurplus_.minimalCollectAmount
              : minimalTransfer;
          if (totalAssets_ > totalSupply_ + minimalTransfer) {
              //Check if current surplus is high enough
              bool sufficientTransfer;
              unchecked{sufficientTransfer=timeLockedSurplus_.timestamp < uint64(block.timestamp);}
              if (sufficientTransfer) {
                  // 3 day TimeLock on surplus distribution - to avoid donor loss in case of potential NAV up-down bounce
                  uint128 newSurplus;
                  unchecked{newSurplus = uint128(totalAssets_ - totalSupply_);}
                  collectedAmount = newSurplus > timeLockedSurplus_.surplus
                      ? timeLockedSurplus_.surplus
                      : newSurplus;
                  if (collectedAmount > minimalTransfer) {
                      IERC20(asset()).safeTransfer(owner(), collectedAmount);
                  } else {
                      collectedAmount = 0;
                  }
                  unchecked{
                  timeLockedSurplus = TimelockedSurplus(
                      newSurplus - collectedAmount,
                      uint64(block.timestamp + 3 days),
                      timeLockedSurplus_.minimalCollectAmount
                  );
              }
              } //Do nothing if timeLock not elapsed
          }
      }
  
      /* ========== RESTRICTED FUNCTIONS ========== */
  
      /// @notice Allows Owner to set minimalCollectAmount
      function setAutoCollectThreshold(
          uint64 newMinimalCollectAmount
      ) external override(IImpactVault) onlyOwner {
          TimelockedSurplus memory timeLockedSurplus_ = timeLockedSurplus;
          timeLockedSurplus = TimelockedSurplus(
              timeLockedSurplus_.surplus,
              timeLockedSurplus_.timestamp,
              newMinimalCollectAmount
          );
          emit SetAutoCollectThreshold(
              newMinimalCollectAmount,
              timeLockedSurplus_.minimalCollectAmount
          );
      }
  }