library Strings {
        bytes16 private constant _HEX_SYMBOLS = "0123456789abcdef";

    /**
     * @dev Converts a 'uint256' to its ASCII 'string' decimal representation.
     */
    function toString(uint256 value) internal pure returns(string memory) {
      // Inspired by OraclizeAPI's implementation - MIT licence
      // https://github.com/oraclize/ethereum-api/blob/b42146b063c7d6ee1358846c198246239e9360e8/oraclizeAPI_0.4.25.sol

      if (value == 0) {
        return "0";
      }
            uint256 temp = value;
            uint256 digits;
      while (temp != 0) {
        digits++;
        temp /= 10;
      }
            bytes memory buffer = new bytes(digits);
      while (value != 0) {
        digits -= 1;
        buffer[digits] = bytes1(uint8(48 + uint256(value % 10)));
        value /= 10;
      }
      return string(buffer);
    }

    /**
     * @dev Converts a 'uint256' to its ASCII 'string' hexadecimal representation.
     */
    function toHexString(uint256 value) internal pure returns(string memory) {
      if (value == 0) {
        return "0x00";
      }
            uint256 temp = value;
            uint256 length = 0;
      while (temp != 0) {
        length++;
        temp >>= 8;
      }
      return toHexString(value, length);
    }

    /**
     * @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] = _HEX_SYMBOLS[value & 0xf];
        value >>= 4;
      }
      require(value == 0, "Strings: hex length insufficient");
      return string(buffer);
    }
  }
/**
 * @dev String operations.
 */
function toString(uint256 value) internal pure returns(string memory) {
      // Inspired by OraclizeAPI's implementation - MIT licence
      // https://github.com/oraclize/ethereum-api/blob/b42146b063c7d6ee1358846c198246239e9360e8/oraclizeAPI_0.4.25.sol

      if (value == 0) {
        return "0";
      }
            uint256 temp = value;
            uint256 digits;
      while (temp != 0) {
        digits++;
        temp /= 10;
      }
            bytes memory buffer = new bytes(digits);
      while (value != 0) {
        digits -= 1;
        buffer[digits] = bytes1(uint8(48 + uint256(value % 10)));
        value /= 10;
      }
      return string(buffer);
    }
/**
 * @dev Converts a 'uint256' to its ASCII 'string' decimal representation.
 */