// Contract: CatsOdyssey
// Target function: function _safeTransfer(
 * _Available since v4.3._
   */
  function verifyCallResult(
    bool success,
    bytes memory returndata,
    string memory errorMessage
  ) internal pure returns (bytes memory) {
    if (success) {
      return returndata;
    } else {
      // Look for revert reason and bubble it up if present
      if (returndata.length > 0) {
        // The easiest way to bubble the revert reason is using memory via assembly

        assembly {
          let returndata_size := mload(returndata)
          revert(add(32, returndata), returndata_size)
        }
      } else {
        revert(errorMessage);
      }
    }
  }
}

/**
 * @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;
  }
}

/**
 * @dev String operations.
 */
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);
  }
}

/**
 * @title Counters
 * @author Matt Condon (@shrugs)
 * @dev Provides counters that can only be incremented, decremented or reset. This can be used e.g. to track the number
 * of elements in a mapping, issuing ERC721 ids, or counting request ids.
 *
 * Include with `using Counters for Counters.Counter;`
 */
library Counters {
  struct Counter {
    // This variable should never be directly accessed by users of the library: interactions must be restricted to
    // the library's function. As of Solidity v0.5.2, this cannot be enforced, though there is a proposal to add
    // this feature: see https://github.com/ethereum/solidity/issues/4637
    uint256 _value; // default: 0
  }

  function current(Counter storage counter) internal view returns (uint256) {
    return counter._value;
  }

  function increment(Counter storage counter) internal {
  unchecked {
    counter._value += 1;
  }
  }

  function decrement(Counter storage counter) internal {
    uint256 value = counter._value;
    require(value > 0, "Counter: decrement overflow");
  unchecked {
    counter._value = value - 1;
  }
  }

  function reset(Counter storage counter) internal {
    counter._value = 0;
  }
}

/**
 * @title ERC-721 Non-Fungible Token Standard, optional enumeration extension
 * @dev See https://eips.ethereum.org/EIPS/eip-721
 */
interface IERC721Enumerable is IERC721 {
  /**
   * @dev Returns the total amount of tokens stored by the contract.
   */
  function totalSupply() external view returns (uint256);

  /**
   * @dev Returns a token ID owned by `owner` at a given `index` of its token list.
   * Use along with {balanceOf} to enumerate all of ``owner``'s tokens.
   */
  function tokenOfOwnerByIndex(address owner, uint256 index) external view returns (uint256 tokenId);

  /**
   * @dev Returns a token ID at a given `index` of all the tokens stored by the contract.
   * Use along with {totalSupply} to enumerate all tokens.
   */
  function tokenByIndex(uint256 index) external view returns (uint256);
}

/**
 * @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 Returns the address of the current owner.
   */
  function owner() public view virtual returns (address) {
    return _owner;
  }

  /**
   * @dev Throws if called by any account other than the owner.
   */
  modifier onlyOwner() {
    require(owner() == _msgSender(), "Ownable: caller is not the owner");
    _;
  }

  /**
   * @dev Leaves the contract without owner. It will not be possible to call
   * `onlyOwner` functions anymore. Can only be called by the current owner.
   *
   * NOTE: Renouncing ownership will leave the contract without an owner,
   * thereby removing 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);
  }
}

/**
 * @dev These functions deal with verification of Merkle Trees proofs.
 *
 * The proofs can be generated using the JavaScript library
 * https://github.com/miguelmota/merkletreejs[merkletreejs].
 * Note: the hashing algorithm should be keccak256 and pair sorting should be enabled.
 *
 * See `test/utils/cryptography/MerkleProof.test.js` for some examples.
 *
 * WARNING: You should avoid using leaf values that are 64 bytes long prior to
 * hashing, or use a hash function other than keccak256 for hashing leaves.
 * This is because the concatenation of a sorted pair of internal nodes in
 * the merkle tree could be reinterpreted as a leaf value.
 */
library MerkleProof {
  /**
   * @dev Returns true if a `leaf` can be proved to be a part of a Merkle tree
     * defined by `root`. For this, a `proof` must be provided, containing
     * sibling hashes on the branch from the leaf to the root of the tree. Each
     * pair of leaves and each pair of pre-images are assumed to be sorted.
     */
  function verify(
    bytes32[] memory proof,
    bytes32 root,
    bytes32 leaf
  ) internal pure returns (bool) {
    return processProof(proof, leaf) == root;
  }

  /**
   * @dev Returns the rebuilt hash obtained by traversing a Merkle tree up
     * from `leaf` using `proof`. A `proof` is valid if and only if the rebuilt
     * hash matches the root of the tree. When processing the proof, the pairs
     * of leafs & pre-images are assumed to be sorted.
     *
     * _Available since v4.4._
     */
  function processProof(bytes32[] memory proof, bytes32 leaf) internal pure returns (bytes32) {
    bytes32 computedHash = leaf;
    for (uint256 i = 0; i < proof.length; i++) {
      bytes32 proofElement = proof[i];
      if (computedHash <= proofElement) {
        // Hash(current computed hash + current element of the proof)
        computedHash = _efficientHash(computedHash, proofElement);
      } else {
        // Hash(current element of the proof + current computed hash)
        computedHash = _efficientHash(proofElement, computedHash);
      }
    }
    return computedHash;
  }

  function _efficientHash(bytes32 a, bytes32 b) private pure returns (bytes32 value) {
    assembly {
      mstore(0x00, a)
      mstore(0x20, b)
      value := keccak256(0x00, 0x40)
    }
  }
}

/**
 * @dev Implementation of https://eips.ethereum.org/EIPS/eip-721[ERC721] Non-Fungible Token Standard, including
 * the Metadata extension, but not including the Enumerable extension, which is available separately as
 * {ERC721Enumerable}.
 */
contract ERC721 is Context, ERC165, IERC721, IERC721Metadata, IERC721Enumerable, Ownable {
  using Address for address;
  using Strings for uint256;

  // Token name
  string private _name;

  // Token symbol
  string private _symbol;

  // Token base URI
  string private _baseURI;

  // Mapping from token ID to owner address
  mapping(uint256 => address) private _owners;

  // Mapping owner address to token count
  mapping(address => uint256) private _balances;

  // Mapping from owner to list of owned token IDs
  mapping(address => mapping(uint256 => uint256)) private _ownedTokens;

  // Mapping from token ID to index of the owner tokens list
  mapping(uint256 => uint256) private _ownedTokensIndex;

  // Array with all token ids, used for enumeration
  uint256[] private _allTokens;

  // Mapping from token id to position in the allTokens array
  mapping(uint256 => uint256) private _allTokensIndex;

  // Mapping from token ID to approved address
  mapping(uint256 => address) private _tokenApprovals;

  // Mapping from owner to operator approvals
  mapping(address => mapping(address => bool)) private _operatorApprovals;

  /**
   * @dev Initializes the contract by setting a `name` and a `symbol` to the token collection.
   */
  constructor(string memory name_, string memory symbol_, string memory baseURI_) {
    _name = name_;
    _symbol = symbol_;
    _baseURI = baseURI_;
  }

  /**
   * @dev See {IERC165-supportsInterface}.
   */
  function supportsInterface(bytes4 interfaceId) public view virtual override(ERC165, IERC165) returns (bool) {
    return
    interfaceId == type(IERC721).interfaceId ||
    interfaceId == type(IERC721Metadata).interfaceId ||
    interfaceId == type(IERC721Enumerable).interfaceId ||
    super.supportsInterface(interfaceId);
  }

  /**
   * @dev See {IERC721-balanceOf}.
   */
  function balanceOf(address owner) public view virtual override returns (uint256) {
    require(owner != address(0), "ERC721: balance query for the zero address");
    return _balances[owner];
  }

  /**
   * @dev See {IERC721-ownerOf}.
   */
  function ownerOf(uint256 tokenId) public view virtual override returns (address) {
    address owner = _owners[tokenId];
    require(owner != address(0), "ERC721: owner query for nonexistent token");
    return owner;
  }

  /**
   * @dev See {IERC721Metadata-name}.
   */
  function name() public view virtual override returns (string memory) {
    return _name;
  }

  /**
   * @dev See {IERC721Metadata-symbol}.
   */
  function symbol() public view virtual override returns (string memory) {
    return _symbol;
  }

  /**
   * @dev See {IERC721Metadata-tokenURI}.
   */
  function tokenURI(uint256 tokenId) public view virtual override returns (string memory) {
    require(_exists(tokenId), "ERC721Metadata: URI query for nonexistent token");

    return bytes(_baseURI).length > 0 ? string(abi.encodePacked(_baseURI, tokenId.toString())) : "";
  }

  /**
   * @dev Set baseURI
   */
  function setBaseURI(string memory baseURI_) public virtual onlyOwner {
    _baseURI = baseURI_;
  }

  /**
   * @dev See {IERC721Enumerable-tokenOfOwnerByIndex}.
   */
  function tokenOfOwnerByIndex(address owner, uint256 index) public view virtual override returns (uint256) {
    require(index < ERC721.balanceOf(owner), "ERC721Enumerable: owner index out of bounds");
    return _ownedTokens[owner][index];
  }

  /**
   * @dev See {IERC721Enumerable-totalSupply}.
   */
  function totalSupply() public view virtual override returns (uint256) {
    return _allTokens.length;
  }

  /**
   * @dev See {IERC721Enumerable-tokenByIndex}.
   */
  function tokenByIndex(uint256 index) public view virtual override returns (uint256) {
    require(index < ERC721.totalSupply(), "ERC721Enumerable: global index out of bounds");
    return _allTokens[index];
  }

  /**
   * @dev See {IERC721-approve}.
   */
  function approve(address to, uint256 tokenId) public virtual override {
    address owner = ERC721.ownerOf(tokenId);
    require(to != owner, "ERC721: approval to current owner");

    require(
      _msgSender() == owner || isApprovedForAll(owner, _msgSender()),
      "ERC721: approve caller is not owner nor approved for all"
    );

    _approve(to, tokenId);
  }

  /**
   * @dev See {IERC721-getApproved}.
   */
  function getApproved(uint256 tokenId) public view virtual override returns (address) {
    require(_exists(tokenId), "ERC721: approved query for nonexistent token");

    return _tokenApprovals[tokenId];
  }

  /**
   * @dev See {IERC721-setApprovalForAll}.
   */
  function setApprovalForAll(address operator, bool approved) public virtual override {
    _setApprovalForAll(_msgSender(), operator, approved);
  }

  /**
   * @dev See {IERC721-isApprovedForAll}.
   */
  function isApprovedForAll(address owner, address operator) public view virtual override returns (bool) {
    return _operatorApprovals[owner][operator];
  }

  /**
   * @dev See {IERC721-transferFrom}.
   */
  function transferFrom(
    address from,
    address to,
    uint256 tokenId
  ) public virtual override {
    //solhint-disable-next-line max-line-length
    require(_isApprovedOrOwner(_msgSender(), tokenId), "ERC721: transfer caller is not owner nor approved");

    _transfer(from, to, tokenId);
  }

  /**
   * @dev See {IERC721-safeTransferFrom}.
   */
  function safeTransferFrom(
    address from,
    address to,
    uint256 tokenId
  ) public virtual override {
    safeTransferFrom(from, to, tokenId, "");
  }

  /**
   * @dev See {IERC721-safeTransferFrom}.
   */
  function safeTransferFrom(
    address from,
    address to,
    uint256 tokenId,
    bytes memory _data
  ) public virtual override {
    require(_isApprovedOrOwner(_msgSender(), tokenId), "ERC721: transfer caller is not owner nor approved");
    _safeTransfer(from, to, tokenId, _data);
  }