creation_sourcecode: //SPDX-License-Identifier: UNLICENSED
  
  pragma solidity ^0.8.0;
  // File: @openzeppelin/contracts/utils/ReentrancyGuard.sol
  // OpenZeppelin Contracts (last updated v5.0.0) (utils/ReentrancyGuard.sol)
  pragma solidity ^0.8.20;
  /**
   * @dev Contract module that helps prevent reentrant calls to a function.
   *
   * Inheriting from `ReentrancyGuard` will make the {nonReentrant} modifier
   * available, which can be applied to functions to make sure there are no nested
   * (reentrant) calls to them.
   *
   * Note that because there is a single `nonReentrant` guard, functions marked as
   * `nonReentrant` may not call one another. This can be worked around by making
   * those functions `private`, and then adding `external` `nonReentrant` entry
   * points to them.
   *
   * TIP: If you would like to learn more about reentrancy and alternative ways
   * to protect against it, check out our blog post
   * https://blog.openzeppelin.com/reentrancy-after-istanbul/[Reentrancy After Istanbul].
   */
  abstract contract ReentrancyGuard {
      // Booleans are more expensive than uint256 or any type that takes up a full
      // word because each write operation emits an extra SLOAD to first read the
      // slot's contents, replace the bits taken up by the boolean, and then write
      // back. This is the compiler's defense against contract upgrades and
      // pointer aliasing, and it cannot be disabled.
  
      // The values being non-zero value makes deployment a bit more expensive,
      // but in exchange the refund on every call to nonReentrant will be lower in
      // amount. Since refunds are capped to a percentage of the total
      // transaction's gas, it is best to keep them low in cases like this one, to
      // increase the likelihood of the full refund coming into effect.
      uint256 private constant NOT_ENTERED = 1;
      uint256 private constant ENTERED = 2;
  
      uint256 private _status;
  
      /**
       * @dev Unauthorized reentrant call.
       */
      error ReentrancyGuardReentrantCall();
  
      constructor() {
          _status = NOT_ENTERED;
      }
  
      /**
       * @dev Prevents a contract from calling itself, directly or indirectly.
       * Calling a `nonReentrant` function from another `nonReentrant`
       * function is not supported. It is possible to prevent this from happening
       * by making the `nonReentrant` function external, and making it call a
       * `private` function that does the actual work.
       */
      modifier nonReentrant() {
          _nonReentrantBefore();
          _;
          _nonReentrantAfter();
      }
  
      function _nonReentrantBefore() private {
          // On the first call to nonReentrant, _status will be NOT_ENTERED
          if (_status == ENTERED) {
              revert ReentrancyGuardReentrantCall();
          }
  
          // Any calls to nonReentrant after this point will fail
          _status = ENTERED;
      }
  
      function _nonReentrantAfter() private {
          // By storing the original value once again, a refund is triggered (see
          // https://eips.ethereum.org/EIPS/eip-2200)
          _status = NOT_ENTERED;
      }
  
      /**
       * @dev Returns true if the reentrancy guard is currently set to "entered", which indicates there is a
       * `nonReentrant` function in the call stack.
       */
      function _reentrancyGuardEntered() internal view returns (bool) {
          return _status == ENTERED;
      }
  }
  
  // File: @openzeppelin/contracts/utils/math/SignedMath.sol
  
  
  // OpenZeppelin Contracts (last updated v5.0.0) (utils/math/SignedMath.sol)
  
  pragma solidity ^0.8.20;
  
  /**
   * @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 v5.0.0) (utils/math/Math.sol)
  
  pragma solidity ^0.8.20;
  
  /**
   * @dev Standard math utilities missing in the Solidity language.
   */
  library Math {
      /**
       * @dev Muldiv operation overflow.
       */
      error MathOverflowedMulDiv();
  
      enum Rounding {
          Floor, // Toward negative infinity
          Ceil, // Toward positive infinity
          Trunc, // Toward zero
          Expand // Away from zero
      }
  
      /**
       * @dev Returns the addition of two unsigned integers, with an overflow flag.
       */
      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.
       */
      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.
       */
      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.
       */
      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.
       */
      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 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 towards infinity instead
       * of rounding towards zero.
       */
      function ceilDiv(uint256 a, uint256 b) internal pure returns (uint256) {
          if (b == 0) {
              // Guarantee the same behavior as in a regular Solidity division.
              return a / b;
          }
  
          // (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 = x * y; // Least significant 256 bits of the product
              uint256 prod1; // Most significant 256 bits of the product
              assembly {
                  let mm := mulmod(x, y, not(0))
                  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.
              if (denominator <= prod1) {
                  revert MathOverflowedMulDiv();
              }
  
              ///////////////////////////////////////////////
              // 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.
  
              uint256 twos = denominator & (0 - denominator);
              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 (unsignedRoundsUp(rounding) && 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
       * towards zero.
       *
       * 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 + (unsignedRoundsUp(rounding) && result * result < a ? 1 : 0);
          }
      }
  
      /**
       * @dev Return the log in base 2 of a positive value rounded towards zero.
       * 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 + (unsignedRoundsUp(rounding) && 1 << result < value ? 1 : 0);
          }
      }
  
      /**
       * @dev Return the log in base 10 of a positive value rounded towards zero.
       * 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 + (unsignedRoundsUp(rounding) && 10 ** result < value ? 1 : 0);
          }
      }
  
      /**
       * @dev Return the log in base 256 of a positive value rounded towards zero.
       * 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 + (unsignedRoundsUp(rounding) && 1 << (result << 3) < value ? 1 : 0);
          }
      }
  
      /**
       * @dev Returns whether a provided rounding mode is considered rounding up for unsigned integers.
       */
      function unsignedRoundsUp(Rounding rounding) internal pure returns (bool) {
          return uint8(rounding) % 2 == 1;
      }
  }
  
  // File: @openzeppelin/contracts/utils/Strings.sol
  
  
  // OpenZeppelin Contracts (last updated v5.0.0) (utils/Strings.sol)
  
  pragma solidity ^0.8.20;
  
  /**
   * @dev String operations.
   */
  library Strings {
      bytes16 private constant HEX_DIGITS = "0123456789abcdef";
      uint8 private constant ADDRESS_LENGTH = 20;
  
      /**
       * @dev The `value` string doesn't fit in the specified `length`.
       */
      error StringsInsufficientHexLength(uint256 value, uint256 length);
  
      /**
       * @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), HEX_DIGITS))
                  }
                  value /= 10;
                  if (value == 0) break;
              }
              return buffer;
          }
      }
  
      /**
       * @dev Converts a `int256` to its ASCII `string` decimal representation.
       */
      function toStringSigned(int256 value) internal pure returns (string memory) {
          return string.concat(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) {
          uint256 localValue = value;
          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] = HEX_DIGITS[localValue & 0xf];
              localValue >>= 4;
          }
          if (localValue != 0) {
              revert StringsInsufficientHexLength(value, length);
          }
          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 bytes(a).length == bytes(b).length && keccak256(bytes(a)) == keccak256(bytes(b));
      }
  }
  
  // File: @openzeppelin/contracts/utils/Context.sol
  // OpenZeppelin Contracts (last updated v5.0.1) (utils/Context.sol)
  
  pragma solidity ^0.8.20;
  
  /**
   * @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/utils/Pausable.sol
  
  
  // OpenZeppelin Contracts (last updated v5.0.0) (utils/Pausable.sol)
  
  pragma solidity ^0.8.20;
  
  
  /**
   * @dev Contract module which allows children to implement an emergency stop
   * mechanism that can be triggered by an authorized account.
   *
   * This module is used through inheritance. It will make available the
   * modifiers `whenNotPaused` and `whenPaused`, which can be applied to
   * the functions of your contract. Note that they will not be pausable by
   * simply including this module, only once the modifiers are put in place.
   */
  abstract contract Pausable is Context {
      bool private _paused;
  
      /**
       * @dev Emitted when the pause is triggered by `account`.
       */
      event Paused(address account);
  
      /**
       * @dev Emitted when the pause is lifted by `account`.
       */
      event Unpaused(address account);
  
      /**
       * @dev The operation failed because the contract is paused.
       */
      error EnforcedPause();
  
      /**
       * @dev The operation failed because the contract is not paused.
       */
      error ExpectedPause();
  
      /**
       * @dev Initializes the contract in unpaused state.
       */
      constructor() {
          _paused = false;
      }
  
      /**
       * @dev Modifier to make a function callable only when the contract is not paused.
       *
       * Requirements:
       *
       * - The contract must not be paused.
       */
      modifier whenNotPaused() {
          _requireNotPaused();
          _;
      }
  
      /**
       * @dev Modifier to make a function callable only when the contract is paused.
       *
       * Requirements:
       *
       * - The contract must be paused.
       */
      modifier whenPaused() {
          _requirePaused();
          _;
      }
  
      /**
       * @dev Returns true if the contract is paused, and false otherwise.
       */
      function paused() public view virtual returns (bool) {
          return _paused;
      }
  
      /**
       * @dev Throws if the contract is paused.
       */
      function _requireNotPaused() internal view virtual {
          if (paused()) {
              revert EnforcedPause();
          }
      }
  
      /**
       * @dev Throws if the contract is not paused.
       */
      function _requirePaused() internal view virtual {
          if (!paused()) {
              revert ExpectedPause();
          }
      }
  
      /**
       * @dev Triggers stopped state.
       *
       * Requirements:
       *
       * - The contract must not be paused.
       */
      function _pause() internal virtual whenNotPaused {
          _paused = true;
          emit Paused(_msgSender());
      }
  
      /**
       * @dev Returns to normal state.
       *
       * Requirements:
       *
       * - The contract must be paused.
       */
      function _unpause() internal virtual whenPaused {
          _paused = false;
          emit Unpaused(_msgSender());
      }
  }
  
  // File: @openzeppelin/contracts/access/Ownable.sol
  
  
  // OpenZeppelin Contracts (last updated v5.0.0) (access/Ownable.sol)
  
  pragma solidity ^0.8.20;
  
  /**
   * @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.
   *
   * The initial owner is set to the address provided by the deployer. 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;
  
      /**
       * @dev The caller account is not authorized to perform an operation.
       */
      error OwnableUnauthorizedAccount(address account);
  
      /**
       * @dev The owner is not a valid owner account. (eg. `address(0)`)
       */
      error OwnableInvalidOwner(address owner);
  
      event OwnershipTransferred(address indexed previousOwner, address indexed newOwner);
  
      /**
       * @dev Initializes the contract setting the address provided by the deployer as the initial owner.
       */
      constructor(address initialOwner) {
          if (initialOwner == address(0)) {
              revert OwnableInvalidOwner(address(0));
          }
          _transferOwnership(initialOwner);
      }
  
      /**
       * @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 {
          if (owner() != _msgSender()) {
              revert OwnableUnauthorizedAccount(_msgSender());
          }
      }
  
      /**
       * @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 {
          if (newOwner == address(0)) {
              revert OwnableInvalidOwner(address(0));
          }
          _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
  // OpenZeppelin Contracts (last updated v5.0.0) (access/Ownable2Step.sol)
  
  pragma solidity ^0.8.20;
  
  
  /**
   * @dev Contract module which provides access control mechanism, where
   * there is an account (an owner) that can be granted exclusive access to
   * specific functions.
   *
   * The initial owner is specified at deployment time in the constructor for `Ownable`. 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();
          if (pendingOwner() != sender) {
              revert OwnableUnauthorizedAccount(sender);
          }
          _transferOwnership(sender);
      }
  }
  
  // File: contracts/ERC404.sol
  
  pragma solidity ^0.8.0;
  
  
  abstract contract ERC721Receiver {
      function onERC721Received(
          address,
          address,
          uint256,
          bytes calldata
      ) external virtual returns (bytes4) {
          return ERC721Receiver.onERC721Received.selector;
      }
  }
  
  /// @notice ERC404
  ///         A gas-efficient, mixed ERC20 / ERC721 implementation
  ///         with native liquidity and fractionalization.
  ///
  ///         This is an experimental standard designed to integrate
  ///         with pre-existing ERC20 / ERC721 support as smoothly as
  ///         possible.
  ///
  /// @dev    In order to support full functionality of ERC20 and ERC721
  ///         supply assumptions are made that slightly constraint usage.
  ///         Ensure decimals are sufficiently large (standard 18 recommended)
  ///         as ids are effectively encoded in the lowest range of amounts.
  ///
  ///         NFTs are spent on ERC20 functions in a FILO queue, this is by
  ///         design.
  ///
  abstract contract ERC404 is Ownable2Step {
      // Events
      event ERC20Transfer(
          address indexed from,
          address indexed to,
          uint256 amount
      );
      event Approval(
          address indexed owner,
          address indexed spender,
          uint256 amount
      );
      event Transfer(
          address indexed from,
          address indexed to,
          uint256 indexed id
      );
      event ERC721Approval(
          address indexed owner,
          address indexed spender,
          uint256 indexed id
      );
      event ApprovalForAll(
          address indexed owner,
          address indexed operator,
          bool approved
      );
  
      // Errors
      error NotFound();
      error AlreadyExists();
      error InvalidRecipient();
      error InvalidSender();
      error UnsafeRecipient();
      error Unauthorized();
      error InvalidOwner();
  
      // Metadata
      /// @dev Token name
      string public name;
  
      /// @dev Token symbol
      string public symbol;
  
      /// @dev Decimals for fractional representation
      uint8 public immutable decimals;
  
      /// @dev Total supply in fractionalized representation
      uint256 public immutable totalSupply;
  
      /// @dev Current mint counter, monotonically increasing to ensure accurate ownership
      uint256 public minted;
  
      // Mappings
      /// @dev Balance of user in fractional representation
      mapping(address => uint256) public balanceOf;
  
      /// @dev Allowance of user in fractional representation
      mapping(address => mapping(address => uint256)) public allowance;
  
      /// @dev Approval in native representaion
      mapping(uint256 => address) public getApproved;
  
      /// @dev Approval for all in native representation
      mapping(address => mapping(address => bool)) public isApprovedForAll;
  
      /// @dev Owner of id in native representation
      mapping(uint256 => address) internal _ownerOf;
  
      /// @dev Array of owned ids in native representation
      mapping(address => uint256[]) internal _owned;
  
      /// @dev Tracks indices for the _owned mapping
      mapping(uint256 => uint256) internal _ownedIndex;
  
      /// @dev Addresses whitelisted from minting / burning for gas savings (pairs, routers, etc)
      mapping(address => bool) public whitelist;
  
      // Constructor
      constructor(
          string memory _name,
          string memory _symbol,
          uint8 _decimals,
          uint256 _totalNativeSupply,
          address _owner
      ) Ownable(_owner) {
          name = _name;
          symbol = _symbol;
          decimals = _decimals;
          totalSupply = _totalNativeSupply * (10 ** decimals);
      }
  
      /// @notice Initialization function to set pairs / etc
      ///         saving gas by avoiding mint / burn on unnecessary targets
      function setWhitelist(address target, bool state) public onlyOwner {
          whitelist[target] = state;
      }
  
      /// @notice Function to find owner of a given native token
      function ownerOf(uint256 id) public view virtual returns (address owner) {
          owner = _ownerOf[id];
  
          if (owner == address(0)) {
              revert NotFound();
          }
      }
  
      /// @notice tokenURI must be implemented by child contract
      function tokenURI(uint256 id) public view virtual returns (string memory);
  
      /// @notice Function for token approvals
      /// @dev This function assumes id / native if amount less than or equal to current max id
      function approve(
          address spender,
          uint256 amountOrId
      ) public virtual returns (bool) {
          if (amountOrId <= minted && amountOrId > 0) {
              address owner = _ownerOf[amountOrId];
  
              if (msg.sender != owner && !isApprovedForAll[owner][msg.sender]) {
                  revert Unauthorized();
              }
  
              getApproved[amountOrId] = spender;
  
              emit Approval(owner, spender, amountOrId);
          } else {
              allowance[msg.sender][spender] = amountOrId;
  
              emit Approval(msg.sender, spender, amountOrId);
          }
  
          return true;
      }
  
      /// @notice Function native approvals
      function setApprovalForAll(address operator, bool approved) public virtual {
          isApprovedForAll[msg.sender][operator] = approved;
  
          emit ApprovalForAll(msg.sender, operator, approved);
      }
  
      /// @notice Function for mixed transfers
      /// @dev This function assumes id / native if amount less than or equal to current max id
      function transferFrom(
          address from,
          address to,
          uint256 amountOrId
      ) public virtual {
          if (amountOrId <= minted) {
              if (from != _ownerOf[amountOrId]) {
                  revert InvalidSender();
              }
  
              if (to == address(0)) {
                  revert InvalidRecipient();
              }
  
              if (
                  msg.sender != from &&
                  !isApprovedForAll[from][msg.sender] &&
                  msg.sender != getApproved[amountOrId]
              ) {
                  revert Unauthorized();
              }
  
              balanceOf[from] -= _getUnit();
  
              unchecked {
                  balanceOf[to] += _getUnit();
              }
  
              _ownerOf[amountOrId] = to;
              delete getApproved[amountOrId];
  
              // update _owned for sender
              uint256 updatedId = _owned[from][_owned[from].length - 1];
              _owned[from][_ownedIndex[amountOrId]] = updatedId;
              // pop
              _owned[from].pop();
              // update index for the moved id
              _ownedIndex[updatedId] = _ownedIndex[amountOrId];
              // push token to to owned
              _owned[to].push(amountOrId);
              // update index for to owned
              _ownedIndex[amountOrId] = _owned[to].length - 1;
  
              emit Transfer(from, to, amountOrId);
              emit ERC20Transfer(from, to, _getUnit());
          } else {
              uint256 allowed = allowance[from][msg.sender];
  
              if (allowed != type(uint256).max)
                  allowance[from][msg.sender] = allowed - amountOrId;
  
              _transfer(from, to, amountOrId);
          }
      }
  
      /// @notice Function for fractional transfers
      function transfer(
          address to,
          uint256 amount
      ) public virtual returns (bool) {
          return _transfer(msg.sender, to, amount);
      }
  
      /// @notice Function for native transfers with contract support
      function safeTransferFrom(
          address from,
          address to,
          uint256 id
      ) public virtual {
          transferFrom(from, to, id);
  
          if (
              to.code.length != 0 &&
              ERC721Receiver(to).onERC721Received(msg.sender, from, id, "") !=
              ERC721Receiver.onERC721Received.selector
          ) {
              revert UnsafeRecipient();
          }
      }
  
      /// @notice Function for native transfers with contract support and callback data
      function safeTransferFrom(
          address from,
          address to,
          uint256 id,
          bytes calldata data
      ) public virtual {
          transferFrom(from, to, id);
  
          if (
              to.code.length != 0 &&
              ERC721Receiver(to).onERC721Received(msg.sender, from, id, data) !=
              ERC721Receiver.onERC721Received.selector
          ) {
              revert UnsafeRecipient();
          }
      }
  
      /// @notice Internal function for fractional transfers
      function _transfer(
          address from,
          address to,
          uint256 amount
      ) internal virtual returns (bool) {
          uint256 unit = _getUnit();
          uint256 balanceBeforeSender = balanceOf[from];
          uint256 balanceBeforeReceiver = balanceOf[to];
  
          balanceOf[from] -= amount;
  
          unchecked {
              balanceOf[to] += amount;
          }
  
          // Skip burn for certain addresses to save gas
          if (!whitelist[from]) {
              uint256 tokens_to_burn = (balanceBeforeSender / unit) -
                  (balanceOf[from] / unit);
              for (uint256 i = 0; i < tokens_to_burn; i++) {
                  _burn(from);
              }
          }
  
          // Skip minting for certain addresses to save gas
          if (!whitelist[to]) {
              uint256 tokens_to_mint = (balanceOf[to] / unit) -
                  (balanceBeforeReceiver / unit);
              for (uint256 i = 0; i < tokens_to_mint; i++) {
                  _mint(to);
              }
          }
  
          emit ERC20Transfer(from, to, amount);
          return true;
      }
  
      // Internal utility logic
      function _getUnit() internal view returns (uint256) {
          return 20000 * 10 ** decimals;
      }
  
      function _mint(address to) internal virtual {
          if (to == address(0)) {
              revert InvalidRecipient();
          }
  
          unchecked {
              minted++;
          }
  
          uint256 id = minted;
  
          if (_ownerOf[id] != address(0)) {
              revert AlreadyExists();
          }
  
          _ownerOf[id] = to;
          _owned[to].push(id);
          _ownedIndex[id] = _owned[to].length - 1;
  
          emit Transfer(address(0), to, id);
      }
  
      function _burn(address from) internal virtual {
          if (from == address(0)) {
              revert InvalidSender();
          }
  
          uint256 id = _owned[from][_owned[from].length - 1];
          _owned[from].pop();
          delete _ownedIndex[id];
          delete _ownerOf[id];
          delete getApproved[id];
  
          emit Transfer(from, address(0), id);
      }
  
      function _setNameSymbol(
          string memory _name,
          string memory _symbol
      ) internal {
          name = _name;
          symbol = _symbol;
      }
  }
  
  
  
  contract R200 is ERC404, Pausable, ReentrancyGuard {
      string public baseTokenURI;
      uint256 public buyLimit;
      uint256 public sellLimit;
      uint256 public txLimit;
      mapping (address => uint256) public userBuylimit;
      mapping (address => uint256) public userSelllimit;
      using Strings for uint256;
      bool public applyTxLimit;
  
      constructor(
          address _owner,
          uint256 _initialSupply,
          uint8 _decimal,
          uint256 _buylimit,
          uint256 _selllimit
      ) ERC404("R200", "R200", _decimal, _initialSupply, _owner) {
          balanceOf[_owner] = _initialSupply * 10 ** _decimal;
          buyLimit = _buylimit * 10 ** _decimal;
          sellLimit = _selllimit * 10 ** _decimal;
          txLimit = 10 * 10 ** _decimal;
      }
  
      function setLimit(uint256 _buylimit, uint256 _selllimit) public onlyOwner{
          buyLimit = _buylimit;
          sellLimit = _selllimit;
      }
  
      function _mint(
          address to
      ) internal override whenNotPaused{
          return super._mint(to);
      }
  
      function startApplyingLimit() external onlyOwner{
          applyTxLimit = true;
      }
  
      function stopApplyingLimit() external onlyOwner{
          applyTxLimit = false;
      }
  
      function _transfer(
          address from,
          address to,
          uint256 amount
      ) internal override virtual whenNotPaused returns (bool){
          if(applyTxLimit){
              require(amount < txLimit, "exceed tx limit");
          }
          if(!whitelist[from]){
              userSelllimit[from] += amount;
              require(userSelllimit[from] <= sellLimit, "not allowed anymore to sell");
          }
          if(!whitelist[to]){
              userBuylimit[to] += amount;
              require(userBuylimit[to] <= buyLimit, "not allowed anymore to buy");
          }
          return super._transfer(from, to, amount);
      }
  
      function setTokenURI(string memory _tokenURI) public onlyOwner {
          baseTokenURI = _tokenURI;
      }
  
      function setNameSymbol(
          string memory _name,
          string memory _symbol
      ) public onlyOwner {
          _setNameSymbol(_name, _symbol);
      }
  
      
      function tokenURI(uint256 id) public view override returns (string memory) {
          if (id > 50) {
              bytes32 hash = keccak256(abi.encodePacked(id));
              id = uint256(hash) % 50 + 1;
          }
          return bytes(baseTokenURI).length > 0 ? string.concat(baseTokenURI, id.toString(), ".json") : "";
      }
  }