/**
    *Submitted for verification at Etherscan.io on 2022-07-11
    */

    // File: @openzeppelin/contracts/utils/Strings.sol

    // SPDX-License-Identifier: MIT
    pragma solidity ^0.8.0;
    contract TestContract {
    // Some logic
    }

    // OpenZeppelin Contracts v4.4.1 (utils/Strings.sol)

    pragma solidity ^0.8.0;

    /**
    * @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);
        }
    }

    // File: @openzeppelin/contracts/security/ReentrancyGuard.sol


    // OpenZeppelin Contracts v4.4.1 (security/ReentrancyGuard.sol)

    pragma solidity ^0.8.0;

    /**
    * @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;

        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() {
            // On the first call to nonReentrant, _notEntered will be true
            require(_status != _ENTERED, "ReentrancyGuard: reentrant call");

            // Any calls to nonReentrant after this point will fail
            _status = _ENTERED;

            _;

            // By storing the original value once again, a refund is triggered (see
            // https://eips.ethereum.org/EIPS/eip-2200)
            _status = _NOT_ENTERED;
        }
    }

    // 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/Ownable.sol


    // OpenZeppelin Contracts v4.4.1 (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 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);
        }
    }

    // File: erc721a/contracts/IERC721A.sol


    // ERC721A Contracts v4.0.0
    // Creator: Chiru Labs

    pragma solidity ^0.8.4;

    /**
    * @dev Interface of an ERC721A compliant contract.
    */
    interface IERC721A {
        /**
        * The caller must own the token or be an approved operator.
        */
        error ApprovalCallerNotOwnerNorApproved();

        /**
        * The token does not exist.
        */
        error ApprovalQueryForNonexistentToken();

        /**
        * The caller cannot approve to their own address.
        */
        error ApproveToCaller();

        /**
        * The caller cannot approve to the current owner.
        */
        error ApprovalToCurrentOwner();

        /**
        * Cannot query the balance for the zero address.
        */
        error BalanceQueryForZeroAddress();

        /**
        * Cannot mint to the zero address.
        */
        error MintToZeroAddress();

        /**
        * The quantity of tokens minted must be more than zero.
        */
        error MintZeroQuantity();

        /**
        * The token does not exist.
        */
        error OwnerQueryForNonexistentToken();

        /**
        * The caller must own the token or be an approved operator.
        */
        error TransferCallerNotOwnerNorApproved();

        /**
        * The token must be owned by `from`.
        */
        error TransferFromIncorrectOwner();

        /**
        * Cannot safely transfer to a contract that does not implement the ERC721Receiver interface.
        */
        error TransferToNonERC721ReceiverImplementer();

        /**
        * Cannot transfer to the zero address.
        */
        error TransferToZeroAddress();

        /**
        * The token does not exist.
        */
        error URIQueryForNonexistentToken();

        struct TokenOwnership {
            // The address of the owner.
            address addr;
            // Keeps track of the start time of ownership with minimal overhead for tokenomics.
            uint64 startTimestamp;
            // Whether the token has been burned.
            bool burned;
        }

        /**
        * @dev Returns the total amount of tokens stored by the contract.
        *
        * Burned tokens are calculated here, use `_totalMinted()` if you want to count just minted tokens.
        */
        function totalSupply() external view returns (uint256);

        // ==============================
        //            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);

        // ==============================
        //            IERC721
        // ==============================

        /**
        * @dev Emitted when `tokenId` token is transferred from `from` to `to`.
        */
        event Transfer(address indexed from, address indexed to, uint256 indexed tokenId);

        /**
        * @dev Emitted when `owner` enables `approved` to manage the `tokenId` token.
        */
        event Approval(address indexed owner, address indexed approved, uint256 indexed tokenId);

        /**
        * @dev Emitted when `owner` enables or disables (`approved`) `operator` to manage all of its assets.
        */
        event ApprovalForAll(address indexed owner, address indexed operator, bool approved);

        /**
        * @dev Returns the number of tokens in ``owner``'s account.
        */
        function balanceOf(address owner) external view returns (uint256 balance);

        /**
        * @dev Returns the owner of the `tokenId` token.
        *
        * Requirements:
        *
        * - `tokenId` must exist.
        */
        function ownerOf(uint256 tokenId) external view returns (address owner);

        /**
        * @dev Safely transfers `tokenId` token from `from` to `to`.
        *
        * Requirements:
        *
        * - `from` cannot be the zero address.
        * - `to` cannot be the zero address.
        * - `tokenId` token must exist and be owned by `from`.
        * - If the caller is not `from`, it must be approved to move this token by either {approve} or {setApprovalForAll}.
        * - If `to` refers to a smart contract, it must implement {IERC721Receiver-onERC721Received}, which is called upon a safe transfer.
        *
        * Emits a {Transfer} event.
        */
        function safeTransferFrom(
            address from,
            address to,
            uint256 tokenId,
            bytes calldata data
        ) external;

        /**
        * @dev Safely transfers `tokenId` token from `from` to `to`, checking first that contract recipients
        * are aware of the ERC721 protocol to prevent tokens from being forever locked.
        *
        * Requirements:
        *
        * - `from` cannot be the zero address.
        * - `to` cannot be the zero address.
        * - `tokenId` token must exist and be owned by `from`.
        * - If the caller is not `from`, it must be have been allowed to move this token by either {approve} or {setApprovalForAll}.
        * - If `to` refers to a smart contract, it must implement {IERC721Receiver-onERC721Received}, which is called upon a safe transfer.
        *
        * Emits a {Transfer} event.
        */
        function safeTransferFrom(
            address from,
            address to,
            uint256 tokenId
        ) external;

        /**
        * @dev Transfers `tokenId` token from `from` to `to`.
        *
        * WARNING: Usage of this method is discouraged, use {safeTransferFrom} whenever possible.
        *
        * Requirements:
        *
        * - `from` cannot be the zero address.
        * - `to` cannot be the zero address.
        * - `tokenId` token must be owned by `from`.
        * - If the caller is not `from`, it must be approved to move this token by either {approve} or {setApprovalForAll}.
        *
        * Emits a {Transfer} event.
        */
        function transferFrom(
            address from,
            address to,
            uint256 tokenId
        ) external;

        /**
        * @dev Gives permission to `to` to transfer `tokenId` token to another account.
        * The approval is cleared when the token is transferred.
        *
        * Only a single account can be approved at a time, so approving the zero address clears previous approvals.
        *
        * Requirements:
        *
        * - The caller must own the token or be an approved operator.
        * - `tokenId` must exist.
        *
        * Emits an {Approval} event.
        */
        function approve(address to, uint256 tokenId) external;

        /**
        * @dev Approve or remove `operator` as an operator for the caller.
        * Operators can call {transferFrom} or {safeTransferFrom} for any token owned by the caller.
        *
        * Requirements:
        *
        * - The `operator` cannot be the caller.
        *
        * Emits an {ApprovalForAll} event.
        */
        function setApprovalForAll(address operator, bool _approved) external;

        /**
        * @dev Returns the account approved for `tokenId` token.
        *
        * Requirements:
        *
        * - `tokenId` must exist.
        */
        function getApproved(uint256 tokenId) external view returns (address operator);

        /**
        * @dev Returns if the `operator` is allowed to manage all of the assets of `owner`.
        *
        * See {setApprovalForAll}
        */
        function isApprovedForAll(address owner, address operator) external view returns (bool);

        // ==============================
        //        IERC721Metadata
        // ==============================

        /**
        * @dev Returns the token collection name.
        */
        function name() external view returns (string memory);

        /**
        * @dev Returns the token collection symbol.
        */
        function symbol() external view returns (string memory);

        /**
        * @dev Returns the Uniform Resource Identifier (URI) for `tokenId` token.
        */
        function tokenURI(uint256 tokenId) external view returns (string memory);
    }

    // File: erc721a/contracts/ERC721A.sol


    // ERC721A Contracts v4.0.0
    // Creator: Chiru Labs

    pragma solidity ^0.8.4;


    /**
    * @dev ERC721 token receiver interface.
    */
    interface ERC721A__IERC721Receiver {
        function onERC721Received(
            address operator,
            address from,
            uint256 tokenId,
            bytes calldata data
        ) external returns (bytes4);
    }

    /**
    * @dev Implementation of https://eips.ethereum.org/EIPS/eip-721[ERC721] Non-Fungible Token Standard, including
    * the Metadata extension. Built to optimize for lower gas during batch mints.
    *
    * Assumes serials are sequentially minted starting at _startTokenId() (defaults to 0, e.g. 0, 1, 2, 3..).
    *
    * Assumes that an owner cannot have more than 2**64 - 1 (max value of uint64) of supply.
    *
    * Assumes that the maximum token id cannot exceed 2**256 - 1 (max value of uint256).
    */
    contract ERC721A is IERC721A {
        // Mask of an entry in packed address data.
        uint256 private constant BITMASK_ADDRESS_DATA_ENTRY = (1 << 64) - 1;

        // The bit position of `numberMinted` in packed address data.
        uint256 private constant BITPOS_NUMBER_MINTED = 64;

        // The bit position of `numberBurned` in packed address data.
        uint256 private constant BITPOS_NUMBER_BURNED = 128;

        // The bit position of `aux` in packed address data.
        uint256 private constant BITPOS_AUX = 192;

        // Mask of all 256 bits in packed address data except the 64 bits for `aux`.
        uint256 private constant BITMASK_AUX_COMPLEMENT = (1 << 192) - 1;

        // The bit position of `startTimestamp` in packed ownership.
        uint256 private constant BITPOS_START_TIMESTAMP = 160;

        // The bit mask of the `burned` bit in packed ownership.
        uint256 private constant BITMASK_BURNED = 1 << 224;
        
        // The bit position of the `nextInitialized` bit in packed ownership.
        uint256 private constant BITPOS_NEXT_INITIALIZED = 225;

        // The bit mask of the `nextInitialized` bit in packed ownership.
        uint256 private constant BITMASK_NEXT_INITIALIZED = 1 << 225;

        // The tokenId of the next token to be minted.
        uint256 private _currentIndex;

        // The number of tokens burned.
        uint256 private _burnCounter;

        // Token name
        string private _name;

        // Token symbol
        string private _symbol;

        // Mapping from token ID to ownership details
        // An empty struct value does not necessarily mean the token is unowned.
        // See `_packedOwnershipOf` implementation for details.
        //
        // Bits Layout:
        // - [0..159]   `addr`
        // - [160..223] `startTimestamp`
        // - [224]      `burned`
        // - [225]      `nextInitialized`
        mapping(uint256 => uint256) private _packedOwnerships;

        // Mapping owner address to address data.
        //
        // Bits Layout:
        // - [0..63]    `balance`
        // - [64..127]  `numberMinted`
        // - [128..191] `numberBurned`
        // - [192..255] `aux`
        mapping(address => uint256) private _packedAddressData;

        // 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;

        constructor(string memory name_, string memory symbol_) {
            _name = name_;
            _symbol = symbol_;
            _currentIndex = _startTokenId();
        }

        /**
        * @dev Returns the starting token ID. 
        * To change the starting token ID, please override this function.
        */
        function _startTokenId() internal view virtual returns (uint256) {
            return 0;
        }

        /**
        * @dev Returns the next token ID to be minted.
        */
        function _nextTokenId() internal view returns (uint256) {
            return _currentIndex;
        }

        /**
        * @dev Returns the total number of tokens in existence.
        * Burned tokens will reduce the count. 
        * To get the total number of tokens minted, please see `_totalMinted`.
        */
        function totalSupply() public view override returns (uint256) {
            // Counter underflow is impossible as _burnCounter cannot be incremented
            // more than `_currentIndex - _startTokenId()` times.
            unchecked {
                return _currentIndex - _burnCounter - _startTokenId();
            }
        }

        /**
        * @dev Returns the total amount of tokens minted in the contract.
        */
        function _totalMinted() internal view returns (uint256) {
            // Counter underflow is impossible as _currentIndex does not decrement,
            // and it is initialized to `_startTokenId()`
            unchecked {
                return _currentIndex - _startTokenId();
            }
        }

        /**
        * @dev Returns the total number of tokens burned.
        */
        function _totalBurned() internal view returns (uint256) {
            return _burnCounter;
        }

        /**
        * @dev See {IERC165-supportsInterface}.
        */
        function supportsInterface(bytes4 interfaceId) public view virtual override returns (bool) {
            // The interface IDs are constants representing the first 4 bytes of the XOR of
            // all function selectors in the interface. See: https://eips.ethereum.org/EIPS/eip-165
            // e.g. `bytes4(i.functionA.selector ^ i.functionB.selector ^ ...)`
            return
                interfaceId == 0x01ffc9a7 || // ERC165 interface ID for ERC165.
                interfaceId == 0x80ac58cd || // ERC165 interface ID for ERC721.
                interfaceId == 0x5b5e139f; // ERC165 interface ID for ERC721Metadata.
        }

        /**
        * @dev See {IERC721-balanceOf}.
        */
        function balanceOf(address owner) public view override returns (uint256) {
            if (owner == address(0)) revert BalanceQueryForZeroAddress();
            return _packedAddressData[owner] & BITMASK_ADDRESS_DATA_ENTRY;
        }

        /**
        * Returns the number of tokens minted by `owner`.
        */
        function _numberMinted(address owner) internal view returns (uint256) {
            return (_packedAddressData[owner] >> BITPOS_NUMBER_MINTED) & BITMASK_ADDRESS_DATA_ENTRY;
        }

        /**
        * Returns the number of tokens burned by or on behalf of `owner`.
        */
        function _numberBurned(address owner) internal view returns (uint256) {
            return (_packedAddressData[owner] >> BITPOS_NUMBER_BURNED) & BITMASK_ADDRESS_DATA_ENTRY;
        }

        /**
        * Returns the auxillary data for `owner`. (e.g. number of whitelist mint slots used).
        */
        function _getAux(address owner) internal view returns (uint64) {
            return uint64(_packedAddressData[owner] >> BITPOS_AUX);
        }

        /**
        * Sets the auxillary data for `owner`. (e.g. number of whitelist mint slots used).
        * If there are multiple variables, please pack them into a uint64.
        */
        function _setAux(address owner, uint64 aux) internal {
            uint256 packed = _packedAddressData[owner];
            uint256 auxCasted;
            assembly { // Cast aux without masking.
                auxCasted := aux
            }
            packed = (packed & BITMASK_AUX_COMPLEMENT) | (auxCasted << BITPOS_AUX);
            _packedAddressData[owner] = packed;
        }

        /**
        * Returns the packed ownership data of `tokenId`.
        */
        function _packedOwnershipOf(uint256 tokenId) private view returns (uint256) {
            uint256 curr = tokenId;

            unchecked {
                if (_startTokenId() <= curr)
                    if (curr < _currentIndex) {
                        uint256 packed = _packedOwnerships[curr];
                        // If not burned.
                        if (packed & BITMASK_BURNED == 0) {
                            // Invariant:
                            // There will always be an ownership that has an address and is not burned
                            // before an ownership that does not have an address and is not burned.
                            // Hence, curr will not underflow.
                            //
                            // We can directly compare the packed value.
                            // If the address is zero, packed is zero.
                            while (packed == 0) {
                                packed = _packedOwnerships[--curr];
                            }
                            return packed;
                        }
                    }
            }
            revert OwnerQueryForNonexistentToken();
        }

        /**
        * Returns the unpacked `TokenOwnership` struct from `packed`.
        */
        function _unpackedOwnership(uint256 packed) private pure returns (TokenOwnership memory ownership) {
            ownership.addr = address(uint160(packed));
            ownership.startTimestamp = uint64(packed >> BITPOS_START_TIMESTAMP);
            ownership.burned = packed & BITMASK_BURNED != 0;
        }

        /**
        * Returns the unpacked `TokenOwnership` struct at `index`.
        */
        function _ownershipAt(uint256 index) internal view returns (TokenOwnership memory) {
            return _unpackedOwnership(_packedOwnerships[index]);
        }

        /**
        * @dev Initializes the ownership slot minted at `index` for efficiency purposes.
        */
        function _initializeOwnershipAt(uint256 index) internal {
            if (_packedOwnerships[index] == 0) {
                _packedOwnerships[index] = _packedOwnershipOf(index);
            }
        }

        /**
        * Gas spent here starts off proportional to the maximum mint batch size.
        * It gradually moves to O(1) as tokens get transferred around in the collection over time.
        */
        function _ownershipOf(uint256 tokenId) internal view returns (TokenOwnership memory) {
            return _unpackedOwnership(_packedOwnershipOf(tokenId));
        }

        /**
        * @dev See {IERC721-ownerOf}.
        */
        function ownerOf(uint256 tokenId) public view override returns (address) {
            return address(uint160(_packedOwnershipOf(tokenId)));
        }

        /**
        * @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) {
            if (!_exists(tokenId)) revert URIQueryForNonexistentToken();

            string memory baseURI = _baseURI();
            return bytes(baseURI).length != 0 ? string(abi.encodePacked(baseURI, _toString(tokenId))) : '';
        }

        /**
        * @dev Base URI for computing {tokenURI}. If set, the resulting URI for each
        * token will be the concatenation of the `baseURI` and the `tokenId`. Empty
        * by default, can be overriden in child contracts.
        */
        function _baseURI() internal view virtual returns (string memory) {
            return '';
        }

        /**
        * @dev Casts the address to uint256 without masking.
        */
        function _addressToUint256(address value) private pure returns (uint256 result) {
            assembly {
                result := value
            }
        }

        /**
        * @dev Casts the boolean to uint256 without branching.
        */
        function _boolToUint256(bool value) private pure returns (uint256 result) {
            assembly {
                result := value
            }
        }

        /**
        * @dev See {IERC721-approve}.
        */
        function approve(address to, uint256 tokenId) public override {
            address owner = address(uint160(_packedOwnershipOf(tokenId)));
            if (to == owner) revert ApprovalToCurrentOwner();

            if (_msgSenderERC721A() != owner)
                if (!isApprovedForAll(owner, _msgSenderERC721A())) {
                    revert ApprovalCallerNotOwnerNorApproved();
                }

            _tokenApprovals[tokenId] = to;
            emit Approval(owner, to, tokenId);
        }

        /**
        * @dev See {IERC721-getApproved}.
        */
        function getApproved(uint256 tokenId) public view override returns (address) {
            if (!_exists(tokenId)) revert ApprovalQueryForNonexistentToken();

            return _tokenApprovals[tokenId];
        }

        /**
        * @dev See {IERC721-setApprovalForAll}.
        */
        function setApprovalForAll(address operator, bool approved) public virtual override {
            if (operator == _msgSenderERC721A()) revert ApproveToCaller();

            _operatorApprovals[_msgSenderERC721A()][operator] = approved;
            emit ApprovalForAll(_msgSenderERC721A(), 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 {
            _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 {
            _transfer(from, to, tokenId);
            if (to.code.length != 0)
                if (!_checkContractOnERC721Received(from, to, tokenId, _data)) {
                    revert TransferToNonERC721ReceiverImplementer();
                }
        }

        /**
        * @dev Returns whether `tokenId` exists.
        *
        * Tokens can be managed by their owner or approved accounts via {approve} or {setApprovalForAll}.
        *
        * Tokens start existing when they are minted (`_mint`),
        */
        function _exists(uint256 tokenId) internal view returns (bool) {
            return
                _startTokenId() <= tokenId &&
                tokenId < _currentIndex && // If within bounds,
                _packedOwnerships[tokenId] & BITMASK_BURNED == 0; // and not burned.
        }

        /**
        * @dev Equivalent to `_safeMint(to, quantity, '')`.
        */
        function _safeMint(address to, uint256 quantity) internal {
            _safeMint(to, quantity, '');
        }

        /**
        * @dev Safely mints `quantity` tokens and transfers them to `to`.
        *
        * Requirements:
        *
        * - If `to` refers to a smart contract, it must implement
        *   {IERC721Receiver-onERC721Received}, which is called for each safe transfer.
        * - `quantity` must be greater than 0.
        *
        * Emits a {Transfer} event.
        */
        function _safeMint(
            address to,
            uint256 quantity,
            bytes memory _data
        ) internal {
            uint256 startTokenId = _currentIndex;
            if (to == address(0)) revert MintToZeroAddress();
            if (quantity == 0) revert MintZeroQuantity();

            _beforeTokenTransfers(address(0), to, startTokenId, quantity);

            // Overflows are incredibly unrealistic.
            // balance or numberMinted overflow if current value of either + quantity > 1.8e19 (2**64) - 1
            // updatedIndex overflows if _currentIndex + quantity > 1.2e77 (2**256) - 1
            unchecked {
                // Updates:
                // - `balance += quantity`.
                // - `numberMinted += quantity`.
                //
                // We can directly add to the balance and number minted.
                _packedAddressData[to] += quantity * ((1 << BITPOS_NUMBER_MINTED) | 1);

                // Updates:
                // - `address` to the owner.
                // - `startTimestamp` to the timestamp of minting.
                // - `burned` to `false`.
                // - `nextInitialized` to `quantity == 1`.
                _packedOwnerships[startTokenId] =
                    _addressToUint256(to) |
                    (block.timestamp << BITPOS_START_TIMESTAMP) |
                    (_boolToUint256(quantity == 1) << BITPOS_NEXT_INITIALIZED);

                uint256 updatedIndex = startTokenId;
                uint256 end = updatedIndex + quantity;

                if (to.code.length != 0) {
                    do {
                        emit Transfer(address(0), to, updatedIndex);
                        if (!_checkContractOnERC721Received(address(0), to, updatedIndex++, _data)) {
                            revert TransferToNonERC721ReceiverImplementer();
                        }
                    } while (updatedIndex < end);
                    // Reentrancy protection
                    if (_currentIndex != startTokenId) revert();
                } else {
                    do {
                        emit Transfer(address(0), to, updatedIndex++);
                    } while (updatedIndex < end);
                }
                _currentIndex = updatedIndex;
            }
            _afterTokenTransfers(address(0), to, startTokenId, quantity);
        }

        /**
        * @dev Mints `quantity` tokens and transfers them to `to`.
        *
        * Requirements:
        *
        * - `to` cannot be the zero address.
        * - `quantity` must be greater than 0.
        *
        * Emits a {Transfer} event.
        */
        function _mint(address to, uint256 quantity) internal {
            uint256 startTokenId = _currentIndex;
            if (to == address(0)) revert MintToZeroAddress();
            if (quantity == 0) revert MintZeroQuantity();

            _beforeTokenTransfers(address(0), to, startTokenId, quantity);

            // Overflows are incredibly unrealistic.
            // balance or numberMinted overflow if current value of either + quantity > 1.8e19 (2**64) - 1
            // updatedIndex overflows if _currentIndex + quantity > 1.2e77 (2**256) - 1
            unchecked {
                // Updates:
                // - `balance += quantity`.
                // - `numberMinted += quantity`.
                //
                // We can directly add to the balance and number minted.
                _packedAddressData[to] += quantity * ((1 << BITPOS_NUMBER_MINTED) | 1);

                // Updates:
                // - `address` to the owner.
                // - `startTimestamp` to the timestamp of minting.
                // - `burned` to `false`.
                // - `nextInitialized` to `quantity == 1`.
                _packedOwnerships[startTokenId] =
                    _addressToUint256(to) |
                    (block.timestamp << BITPOS_START_TIMESTAMP) |
                    (_boolToUint256(quantity == 1) << BITPOS_NEXT_INITIALIZED);

                uint256 updatedIndex = startTokenId;
                uint256 end = updatedIndex + quantity;

                do {
                    emit Transfer(address(0), to, updatedIndex++);
                } while (updatedIndex < end);

                _currentIndex = updatedIndex;
            }
            _afterTokenTransfers(address(0), to, startTokenId, quantity);
        }

        /**
        * @dev Transfers `tokenId` from `from` to `to`.
        *
        * Requirements:
        *
        * - `to` cannot be the zero address.
        * - `tokenId` token must be owned by `from`.
        *
        * Emits a {Transfer} event.
        */
        function _transfer(
            address from,
            address to,
            uint256 tokenId
        ) private {
            uint256 prevOwnershipPacked = _packedOwnershipOf(tokenId);

            if (address(uint160(prevOwnershipPacked)) != from) revert TransferFromIncorrectOwner();

            bool isApprovedOrOwner = (_msgSenderERC721A() == from ||
                isApprovedForAll(from, _msgSenderERC721A()) ||
                getApproved(tokenId) == _msgSenderERC721A());

            if (!isApprovedOrOwner) revert TransferCallerNotOwnerNorApproved();
            if (to == address(0)) revert TransferToZeroAddress();

            _beforeTokenTransfers(from, to, tokenId, 1);

            // Clear approvals from the previous owner.
            delete _tokenApprovals[tokenId];

            // Underflow of the sender's balance is impossible because we check for
            // ownership above and the recipient's balance can't realistically overflow.
            // Counter overflow is incredibly unrealistic as tokenId would have to be 2**256.
            unchecked {
                // We can directly increment and decrement the balances.
                --_packedAddressData[from]; // Updates: `balance -= 1`.
                ++_packedAddressData[to]; // Updates: `balance += 1`.

                // Updates:
                // - `address` to the next owner.
                // - `startTimestamp` to the timestamp of transfering.
                // - `burned` to `false`.
                // - `nextInitialized` to `true`.
                _packedOwnerships[tokenId] =
                    _addressToUint256(to) |
                    (block.timestamp << BITPOS_START_TIMESTAMP) |
                    BITMASK_NEXT_INITIALIZED;

                // If the next slot may not have been initialized (i.e. `nextInitialized == false`) .
                if (prevOwnershipPacked & BITMASK_NEXT_INITIALIZED == 0) {
                    uint256 nextTokenId = tokenId + 1;
                    // If the next slot's address is zero and not burned (i.e. packed value is zero).
                    if (_packedOwnerships[nextTokenId] == 0) {
                        // If the next slot is within bounds.
                        if (nextTokenId != _currentIndex) {
                            // Initialize the next slot to maintain correctness for `ownerOf(tokenId + 1)`.
                            _packedOwnerships[nextTokenId] = prevOwnershipPacked;
                        }
                    }
                }
            }

            emit Transfer(from, to, tokenId);
            _afterTokenTransfers(from, to, tokenId, 1);
        }

        /**
        * @dev Equivalent to `_burn(tokenId, false)`.
        */
        function _burn(uint256 tokenId) internal virtual {
            _burn(tokenId, false);
        }

        /**
        * @dev Destroys `tokenId`.
        * The approval is cleared when the token is burned.
        *
        * Requirements:
        *
        * - `tokenId` must exist.
        *
        * Emits a {Transfer} event.
        */
        function _burn(uint256 tokenId, bool approvalCheck) internal virtual {
            uint256 prevOwnershipPacked = _packedOwnershipOf(tokenId);

            address from = address(uint160(prevOwnershipPacked));

            if (approvalCheck) {
                bool isApprovedOrOwner = (_msgSenderERC721A() == from ||
                    isApprovedForAll(from, _msgSenderERC721A()) ||
                    getApproved(tokenId) == _msgSenderERC721A());

                if (!isApprovedOrOwner) revert TransferCallerNotOwnerNorApproved();
            }

            _beforeTokenTransfers(from, address(0), tokenId, 1);

            // Clear approvals from the previous owner.
            delete _tokenApprovals[tokenId];

            // Underflow of the sender's balance is impossible because we check for
            // ownership above and the recipient's balance can't realistically overflow.
            // Counter overflow is incredibly unrealistic as tokenId would have to be 2**256.
            unchecked {
                // Updates:
                // - `balance -= 1`.
                // - `numberBurned += 1`.
                //
                // We can directly decrement the balance, and increment the number burned.
                // This is equivalent to `packed -= 1; packed += 1 << BITPOS_NUMBER_BURNED;`.
                _packedAddressData[from] += (1 << BITPOS_NUMBER_BURNED) - 1;

                // Updates:
                // - `address` to the last owner.
                // - `startTimestamp` to the timestamp of burning.
                // - `burned` to `true`.
                // - `nextInitialized` to `true`.
                _packedOwnerships[tokenId] =
                    _addressToUint256(from) |
                    (block.timestamp << BITPOS_START_TIMESTAMP) |
                    BITMASK_BURNED | 
                    BITMASK_NEXT_INITIALIZED;

                // If the next slot may not have been initialized (i.e. `nextInitialized == false`) .
                if (prevOwnershipPacked & BITMASK_NEXT_INITIALIZED == 0) {
                    uint256 nextTokenId = tokenId + 1;
                    // If the next slot's address is zero and not burned (i.e. packed value is zero).
                    if (_packedOwnerships[nextTokenId] == 0) {
                        // If the next slot is within bounds.
                        if (nextTokenId != _currentIndex) {
                            // Initialize the next slot to maintain correctness for `ownerOf(tokenId + 1)`.
                            _packedOwnerships[nextTokenId] = prevOwnershipPacked;
                        }
                    }
                }
            }

            emit Transfer(from, address(0), tokenId);
            _afterTokenTransfers(from, address(0), tokenId, 1);

            // Overflow not possible, as _burnCounter cannot be exceed _currentIndex times.
            unchecked {
                _burnCounter++;
            }
        }

        /**
        * @dev Internal function to invoke {IERC721Receiver-onERC721Received} on a target contract.
        *
        * @param from address representing the previous owner of the given token ID
        * @param to target address that will receive the tokens
        * @param tokenId uint256 ID of the token to be transferred
        * @param _data bytes optional data to send along with the call
        * @return bool whether the call correctly returned the expected magic value
        */
        function _checkContractOnERC721Received(
            address from,
            address to,
            uint256 tokenId,
            bytes memory _data
        ) private returns (bool) {
            try ERC721A__IERC721Receiver(to).onERC721Received(_msgSenderERC721A(), from, tokenId, _data) returns (
                bytes4 retval
            ) {
                return retval == ERC721A__IERC721Receiver(to).onERC721Received.selector;
            } catch (bytes memory reason) {
                if (reason.length == 0) {
                    revert TransferToNonERC721ReceiverImplementer();
                } else {
                    assembly {
                        revert(add(32, reason), mload(reason))
                    }
                }
            }
        }

        /**
        * @dev Hook that is called before a set of serially-ordered token ids are about to be transferred. This includes minting.
        * And also called before burning one token.
        *
        * startTokenId - the first token id to be transferred
        * quantity - the amount to be transferred
        *
        * Calling conditions:
        *
        * - When `from` and `to` are both non-zero, `from`'s `tokenId` will be
        * transferred to `to`.
        * - When `from` is zero, `tokenId` will be minted for `to`.
        * - When `to` is zero, `tokenId` will be burned by `from`.
        * - `from` and `to` are never both zero.
        */
        function _beforeTokenTransfers(
            address from,
            address to,
            uint256 startTokenId,
            uint256 quantity
        ) internal virtual {}

        /**
        * @dev Hook that is called after a set of serially-ordered token ids have been transferred. This includes
        * minting.
        * And also called after one token has been burned.
        *
        * startTokenId - the first token id to be transferred
        * quantity - the amount to be transferred
        *
        * Calling conditions:
        *
        * - When `from` and `to` are both non-zero, `from`'s `tokenId` has been
        * transferred to `to`.
        * - When `from` is zero, `tokenId` has been minted for `to`.
        * - When `to` is zero, `tokenId` has been burned by `from`.
        * - `from` and `to` are never both zero.
        */
        function _afterTokenTransfers(
            address from,
            address to,
            uint256 startTokenId,
            uint256 quantity
        ) internal virtual {}

        /**
        * @dev Returns the message sender (defaults to `msg.sender`).
        *
        * If you are writing GSN compatible contracts, you need to override this function.
        */
        function _msgSenderERC721A() internal view virtual returns (address) {
            return msg.sender;
        }

        /**
        * @dev Converts a `uint256` to its ASCII `string` decimal representation.
        */
        function _toString(uint256 value) internal pure returns (string memory ptr) {
            assembly {
                // The maximum value of a uint256 contains 78 digits (1 byte per digit), 
                // but we allocate 128 bytes to keep the free memory pointer 32-byte word aliged.
                // We will need 1 32-byte word to store the length, 
                // and 3 32-byte words to store a maximum of 78 digits. Total: 32 + 3 * 32 = 128.
                ptr := add(mload(0x40), 128)
                // Update the free memory pointer to allocate.
                mstore(0x40, ptr)

                // Cache the end of the memory to calculate the length later.
                let end := ptr

                // We write the string from the rightmost digit to the leftmost digit.
                // The following is essentially a do-while loop that also handles the zero case.
                // Costs a bit more than early returning for the zero case,
                // but cheaper in terms of deployment and overall runtime costs.
                for { 
                    // Initialize and perform the first pass without check.
                    let temp := value
                    // Move the pointer 1 byte leftwards to point to an empty character slot.
                    ptr := sub(ptr, 1)
                    // Write the character to the pointer. 48 is the ASCII index of '0'.
                    mstore8(ptr, add(48, mod(temp, 10)))
                    temp := div(temp, 10)
                } temp { 
                    // Keep dividing `temp` until zero.
                    temp := div(temp, 10)
                } { // Body of the for loop.
                    ptr := sub(ptr, 1)
                    mstore8(ptr, add(48, mod(temp, 10)))
                }
                
                let length := sub(end, ptr)
                // Move the pointer 32 bytes leftwards to make room for the length.
                ptr := sub(ptr, 32)
                // Store the length.
                mstore(ptr, length)
            }
        }
    }

    // File: 000.sol

    pragma solidity ^0.8.0;
    contract TaiwaneseNFT is ERC721A, Ownable {
        using Strings for uint;

        uint public constant MINT_PRICE = 0.002 ether;
        uint public constant MAX_NFT_PER_TRAN = 10;
        uint public constant MAX_PER_WALLET = 100;
        uint public maxSupply = 3999;

        // string private _baseURIExtended;
        bool public isPaused = true;
        bool public isMetadataFinal;
        string public _baseURL;
        string public prerevealURL;
        mapping(address => uint) private _walletMintedCount;

        constructor()
        // Name
        ERC721A('TaiwaneseNFT', 'TWNFT') {
        }

        function _baseURI() internal view override returns (string memory) {
            return _baseURL;
        }

        function _startTokenId() internal pure override returns (uint) {
            return 1;
        }

        function contractURI() public pure returns (string memory) {
            return "";
        }

        function finalizeMetadata() external onlyOwner {
            isMetadataFinal = true;
        }

        function reveal(string memory url) external onlyOwner {
            require(!isMetadataFinal, "Metadata is finalized");
            _baseURL = url;
        }

        function mintedCount(address owner) external view returns (uint) {
            return _walletMintedCount[owner];
        }
        // function setBaseURI(string memory baseURI_) external onlyOwner {
        // _baseURIExtended = baseURI_;
        // }
        function setPause(bool value) external onlyOwner {
            isPaused = value;
        }

        function withdraw() external onlyOwner {
            (bool success, ) = payable(msg.sender).call{
                value: address(this).balance
            }("");
            require(success);
        }

        function devMint(address to, uint count) external onlyOwner {
            require(
                _totalMinted() + count <= maxSupply,
                'Exceeds max supply'
            );
            _safeMint(to, count);
        }

        function setMaxSupply(uint newMaxSupply) external onlyOwner {
            maxSupply = newMaxSupply;
        }

        function tokenURI(uint tokenId)
            public
            view
            override
            returns (string memory)
        {
            require(_exists(tokenId), "ERC721Metadata: URI query for nonexistent token");

            return bytes(_baseURI()).length > 0 
                ? string(abi.encodePacked(_baseURI(), tokenId.toString(), ".json"))
                : prerevealURL;
        }

        function mint(uint count) external payable {
            require(!isPaused, 'Sales are off');
            require(count <= MAX_NFT_PER_TRAN,'Exceeds NFT per transaction limit');
            require(_totalMinted() + count <= maxSupply,'Exceeds max supply');
            require(_walletMintedCount[msg.sender] + count <= MAX_PER_WALLET,'Exceeds max per wallet');

            uint payForCount = count;
            uint mintedSoFar = _walletMintedCount[msg.sender];
            if(mintedSoFar < 2) {
                uint remainingFreeMints = 2 - mintedSoFar;
                if(count > remainingFreeMints) {
                    payForCount = count - remainingFreeMints;
                }
                else {
                    payForCount = 0;
                }
            }

            require(
                msg.value >= payForCount * MINT_PRICE,
                'Ether value sent is not sufficient'
            );

            _walletMintedCount[msg.sender] += count;
            _safeMint(msg.sender, count);
        }

    }