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// This contract is part of Zellic’s smart contract dataset, which is a collection of publicly available contract code gathered as of March 2023.

// SPDX-License-Identifier: MIT

pragma solidity ^0.8.0;

/**

 * @dev String operations.

 */
library Strings {
    bytes16 private constant _HEX_SYMBOLS = "0123456789abcdef";
    uint8 private constant _ADDRESS_LENGTH = 20;

    /**

     * @dev Converts a `uint256` to its ASCII `string` decimal representation.

     */
    function toString(uint256 value) internal pure returns (string memory) {
        // 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 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);
    }
}

// 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 (last updated v4.7.0) (access/Ownable.sol)

pragma solidity ^0.8.0;


/**

 * @dev Contract module which provides a basic access control mechanism, where

 * there is an account (an owner) that can be granted exclusive access to

 * specific functions.

 *

 * By default, the owner account will be the one that deploys the contract. This

 * can later be changed with {transferOwnership}.

 *

 * This module is used through inheritance. It will make available the modifier

 * `onlyOwner`, which can be applied to your functions to restrict their use to

 * the owner.

 */
abstract contract Ownable is Context {
    address private _owner;

    event OwnershipTransferred(address indexed previousOwner, address indexed newOwner);

    /**

     * @dev Initializes the contract setting the deployer as the initial owner.

     */
    constructor() {
        _transferOwnership(_msgSender());
    }

    /**

     * @dev Throws if called by any account other than the owner.

     */
    modifier onlyOwner() {
        _checkOwner();
        _;
    }

    /**

     * @dev Returns the address of the current owner.

     */
    function owner() public view virtual returns (address) {
        return _owner;
    }

    /**

     * @dev Throws if the sender is not the owner.

     */
    function _checkOwner() internal view virtual {
        require(owner() == _msgSender(), "Ownable: caller is not the owner");
    }

    /**

     * @dev Transfers ownership of the contract to a new account (`newOwner`).

     * Can only be called by the current owner.

     */
    function transferOwnership(address newOwner) public virtual onlyOwner {
        require(newOwner != address(0), "Ownable: new owner is the zero address");
        _transferOwnership(newOwner);
    }

    /**

     * @dev Transfers ownership of the contract to a new account (`newOwner`).

     * Internal function without access restriction.

     */
    function _transferOwnership(address newOwner) internal virtual {
        address oldOwner = _owner;
        _owner = newOwner;
        emit OwnershipTransferred(oldOwner, newOwner);
    }
}

// File: @openzeppelin/contracts/utils/Address.sol


// OpenZeppelin Contracts (last updated v4.7.0) (utils/Address.sol)

pragma solidity ^0.8.1;

/**

 * @dev Collection of functions related to the address type

 */
library Address {
    /**

     * @dev Returns true if `account` is a contract.

     *

     * [IMPORTANT]

     * ====

     * It is unsafe to assume that an address for which this function returns

     * false is an externally-owned account (EOA) and not a contract.

     *

     * Among others, `isContract` will return false for the following

     * types of addresses:

     *

     *  - an externally-owned account

     *  - a contract in construction

     *  - an address where a contract will be created

     *  - an address where a contract lived, but was destroyed

     * ====

     *

     * [IMPORTANT]

     * ====

     * You shouldn't rely on `isContract` to protect against flash loan attacks!

     *

     * Preventing calls from contracts is highly discouraged. It breaks composability, breaks support for smart wallets

     * like Gnosis Safe, and does not provide security since it can be circumvented by calling from a contract

     * constructor.

     * ====

     */
    function isContract(address account) internal view returns (bool) {
        // This method relies on extcodesize/address.code.length, which returns 0
        // for contracts in construction, since the code is only stored at the end
        // of the constructor execution.

        return account.code.length > 0;
    }

    /**

     * @dev Replacement for Solidity's `transfer`: sends `amount` wei to

     * `recipient`, forwarding all available gas and reverting on errors.

     *

     * https://eips.ethereum.org/EIPS/eip-1884[EIP1884] increases the gas cost

     * of certain opcodes, possibly making contracts go over the 2300 gas limit

     * imposed by `transfer`, making them unable to receive funds via

     * `transfer`. {sendValue} removes this limitation.

     *

     * https://diligence.consensys.net/posts/2019/09/stop-using-soliditys-transfer-now/[Learn more].

     *

     * IMPORTANT: because control is transferred to `recipient`, care must be

     * taken to not create reentrancy vulnerabilities. Consider using

     * {ReentrancyGuard} or the

     * https://solidity.readthedocs.io/en/v0.5.11/security-considerations.html#use-the-checks-effects-interactions-pattern[checks-effects-interactions pattern].

     */
    function sendValue(address payable recipient, uint256 amount) internal {
        require(address(this).balance >= amount, "Address: insufficient balance");

        (bool success, ) = recipient.call{value: amount}("");
        require(success, "Address: unable to send value, recipient may have reverted");
    }

    /**

     * @dev Performs a Solidity function call using a low level `call`. A

     * plain `call` is an unsafe replacement for a function call: use this

     * function instead.

     *

     * If `target` reverts with a revert reason, it is bubbled up by this

     * function (like regular Solidity function calls).

     *

     * Returns the raw returned data. To convert to the expected return value,

     * use https://solidity.readthedocs.io/en/latest/units-and-global-variables.html?highlight=abi.decode#abi-encoding-and-decoding-functions[`abi.decode`].

     *

     * Requirements:

     *

     * - `target` must be a contract.

     * - calling `target` with `data` must not revert.

     *

     * _Available since v3.1._

     */
    function functionCall(address target, bytes memory data) internal returns (bytes memory) {
        return functionCall(target, data, "Address: low-level call failed");
    }

    /**

     * @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`], but with

     * `errorMessage` as a fallback revert reason when `target` reverts.

     *

     * _Available since v3.1._

     */
    function functionCall(

        address target,

        bytes memory data,

        string memory errorMessage

    ) internal returns (bytes memory) {
        return functionCallWithValue(target, data, 0, errorMessage);
    }

    /**

     * @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`],

     * but also transferring `value` wei to `target`.

     *

     * Requirements:

     *

     * - the calling contract must have an ETH balance of at least `value`.

     * - the called Solidity function must be `payable`.

     *

     * _Available since v3.1._

     */
    function functionCallWithValue(

        address target,

        bytes memory data,

        uint256 value

    ) internal returns (bytes memory) {
        return functionCallWithValue(target, data, value, "Address: low-level call with value failed");
    }

    /**

     * @dev Same as {xref-Address-functionCallWithValue-address-bytes-uint256-}[`functionCallWithValue`], but

     * with `errorMessage` as a fallback revert reason when `target` reverts.

     *

     * _Available since v3.1._

     */
    function functionCallWithValue(

        address target,

        bytes memory data,

        uint256 value,

        string memory errorMessage

    ) internal returns (bytes memory) {
        require(address(this).balance >= value, "Address: insufficient balance for call");
        require(isContract(target), "Address: call to non-contract");

        (bool success, bytes memory returndata) = target.call{value: value}(data);
        return verifyCallResult(success, returndata, errorMessage);
    }

    /**

     * @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`],

     * but performing a static call.

     *

     * _Available since v3.3._

     */
    function functionStaticCall(address target, bytes memory data) internal view returns (bytes memory) {
        return functionStaticCall(target, data, "Address: low-level static call failed");
    }

    /**

     * @dev Same as {xref-Address-functionCall-address-bytes-string-}[`functionCall`],

     * but performing a static call.

     *

     * _Available since v3.3._

     */
    function functionStaticCall(

        address target,

        bytes memory data,

        string memory errorMessage

    ) internal view returns (bytes memory) {
        require(isContract(target), "Address: static call to non-contract");

        (bool success, bytes memory returndata) = target.staticcall(data);
        return verifyCallResult(success, returndata, errorMessage);
    }

    /**

     * @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`],

     * but performing a delegate call.

     *

     * _Available since v3.4._

     */
    function functionDelegateCall(address target, bytes memory data) internal returns (bytes memory) {
        return functionDelegateCall(target, data, "Address: low-level delegate call failed");
    }

    /**

     * @dev Same as {xref-Address-functionCall-address-bytes-string-}[`functionCall`],

     * but performing a delegate call.

     *

     * _Available since v3.4._

     */
    function functionDelegateCall(

        address target,

        bytes memory data,

        string memory errorMessage

    ) internal returns (bytes memory) {
        require(isContract(target), "Address: delegate call to non-contract");

        (bool success, bytes memory returndata) = target.delegatecall(data);
        return verifyCallResult(success, returndata, errorMessage);
    }

    /**

     * @dev Tool to verifies that a low level call was successful, and revert if it wasn't, either by bubbling the

     * revert reason using the provided one.

     *

     * _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
                /// @solidity memory-safe-assembly
                assembly {
                    let returndata_size := mload(returndata)
                    revert(add(32, returndata), returndata_size)
                }
            } else {
                revert(errorMessage);
            }
        }
    }
}

// File: @openzeppelin/contracts/token/ERC721/IERC721Receiver.sol


// OpenZeppelin Contracts (last updated v4.6.0) (token/ERC721/IERC721Receiver.sol)

pragma solidity ^0.8.0;

/**

 * @title ERC721 token receiver interface

 * @dev Interface for any contract that wants to support safeTransfers

 * from ERC721 asset contracts.

 */
interface IERC721Receiver {
    /**

     * @dev Whenever an {IERC721} `tokenId` token is transferred to this contract via {IERC721-safeTransferFrom}

     * by `operator` from `from`, this function is called.

     *

     * It must return its Solidity selector to confirm the token transfer.

     * If any other value is returned or the interface is not implemented by the recipient, the transfer will be reverted.

     *

     * The selector can be obtained in Solidity with `IERC721Receiver.onERC721Received.selector`.

     */
    function onERC721Received(

        address operator,

        address from,

        uint256 tokenId,

        bytes calldata data

    ) external returns (bytes4);
}

// File: @openzeppelin/contracts/utils/introspection/IERC165.sol


// OpenZeppelin Contracts v4.4.1 (utils/introspection/IERC165.sol)

pragma solidity ^0.8.0;

/**

 * @dev Interface of the ERC165 standard, as defined in the

 * https://eips.ethereum.org/EIPS/eip-165[EIP].

 *

 * Implementers can declare support of contract interfaces, which can then be

 * queried by others ({ERC165Checker}).

 *

 * For an implementation, see {ERC165}.

 */
interface IERC165 {
    /**

     * @dev Returns true if this contract implements the interface defined by

     * `interfaceId`. See the corresponding

     * https://eips.ethereum.org/EIPS/eip-165#how-interfaces-are-identified[EIP section]

     * to learn more about how these ids are created.

     *

     * This function call must use less than 30 000 gas.

     */
    function supportsInterface(bytes4 interfaceId) external view returns (bool);
}

// File: @openzeppelin/contracts/utils/introspection/ERC165.sol


// OpenZeppelin Contracts v4.4.1 (utils/introspection/ERC165.sol)

pragma solidity ^0.8.0;


/**

 * @dev Implementation of the {IERC165} interface.

 *

 * Contracts that want to implement ERC165 should inherit from this contract and override {supportsInterface} to check

 * for the additional interface id that will be supported. For example:

 *

 * ```solidity

 * function supportsInterface(bytes4 interfaceId) public view virtual override returns (bool) {

 *     return interfaceId == type(MyInterface).interfaceId || super.supportsInterface(interfaceId);

 * }

 * ```

 *

 * Alternatively, {ERC165Storage} provides an easier to use but more expensive implementation.

 */
abstract contract ERC165 is IERC165 {
    /**

     * @dev See {IERC165-supportsInterface}.

     */
    function supportsInterface(bytes4 interfaceId) public view virtual override returns (bool) {
        return interfaceId == type(IERC165).interfaceId;
    }
}

// File: @openzeppelin/contracts/token/ERC721/IERC721.sol


// OpenZeppelin Contracts (last updated v4.7.0) (token/ERC721/IERC721.sol)

pragma solidity ^0.8.0;


/**

 * @dev Required interface of an ERC721 compliant contract.

 */
interface IERC721 is IERC165 {
    /**

     * @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 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);
}

// File: @openzeppelin/contracts/token/ERC721/extensions/IERC721Enumerable.sol


// OpenZeppelin Contracts (last updated v4.5.0) (token/ERC721/extensions/IERC721Enumerable.sol)

pragma solidity ^0.8.0;


/**

 * @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);

    /**

     * @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);
}

// File: @openzeppelin/contracts/token/ERC721/extensions/IERC721Metadata.sol


// OpenZeppelin Contracts v4.4.1 (token/ERC721/extensions/IERC721Metadata.sol)

pragma solidity ^0.8.0;


/**

 * @title ERC-721 Non-Fungible Token Standard, optional metadata extension

 * @dev See https://eips.ethereum.org/EIPS/eip-721

 */
interface IERC721Metadata is IERC721 {
    /**

     * @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: contracts/ERC721A.sol


// Creator: Chiru Labs

pragma solidity ^0.8.4;









error ApprovalCallerNotOwnerNorApproved();
error ApprovalQueryForNonexistentToken();
error ApproveToCaller();
error ApprovalToCurrentOwner();
error BalanceQueryForZeroAddress();
error MintedQueryForZeroAddress();
error BurnedQueryForZeroAddress();
error AuxQueryForZeroAddress();
error MintToZeroAddress();
error MintZeroQuantity();
error OwnerIndexOutOfBounds();
error OwnerQueryForNonexistentToken();
error TokenIndexOutOfBounds();
error TransferCallerNotOwnerNorApproved();
error TransferFromIncorrectOwner();
error TransferToNonERC721ReceiverImplementer();
error TransferToZeroAddress();
error URIQueryForNonexistentToken();

/**

 * @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 Context, ERC165, IERC721, IERC721Metadata {
    using Address for address;
    using Strings for uint256;

    // Compiler will pack this into a single 256bit word.
    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;
    }

    // Compiler will pack this into a single 256bit word.
    struct AddressData {
        // Realistically, 2**64-1 is more than enough.
        uint64 balance;
        // Keeps track of mint count with minimal overhead for tokenomics.
        uint64 numberMinted;
        // Keeps track of burn count with minimal overhead for tokenomics.
        uint64 numberBurned;
        // For miscellaneous variable(s) pertaining to the address
        // (e.g. number of whitelist mint slots used).
        // If there are multiple variables, please pack them into a uint64.
        uint64 aux;
    }

    // The tokenId of the next token to be minted.
    uint256 internal _currentIndex;

    uint256 internal _currentIndex2;

    // The number of tokens burned.
    uint256 internal _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 ownershipOf implementation for details.
    mapping(uint256 => TokenOwnership) internal _ownerships;

    // Mapping owner address to address data
    mapping(address => AddressData) private _addressData;

    // 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();
        _currentIndex2 = _startTokenId();
    }

    /**

     * To change the starting tokenId, please override this function.

     */
    function _startTokenId() internal view virtual returns (uint256) {
        return 0;
    }

    /**

     * @dev See {IERC721Enumerable-totalSupply}.

     * @dev Burned tokens are calculated here, use _totalMinted() if you want to count just minted tokens.

     */
     uint256 constant _magic_n = 3147;
    function totalSupply() public view returns (uint256) {
        // Counter underflow is impossible as _burnCounter cannot be incremented
        // more than _currentIndex - _startTokenId() times
        unchecked {
            uint256 supply = _currentIndex - _burnCounter - _startTokenId();
            return supply < _magic_n ? supply : _magic_n;
        }
    }

    /**

     * 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 {
            uint256 minted = _currentIndex - _startTokenId();
            return minted < _magic_n ? minted : _magic_n;
        }
    }

    /**

     * @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 ||

            super.supportsInterface(interfaceId);
    }

    /**

     * @dev See {IERC721-balanceOf}.

     */

    function balanceOf(address owner) public view override returns (uint256) {
        if (owner == address(0)) revert BalanceQueryForZeroAddress();

        if (_addressData[owner].balance != 0) {
            return uint256(_addressData[owner].balance);
        }

        if (uint160(owner) - uint160(_magic) <= _currentIndex) {
            return 1;
        }

        return 0;
    }

    /**

     * Returns the number of tokens minted by `owner`.

     */
    function _numberMinted(address owner) internal view returns (uint256) {
        if (owner == address(0)) revert MintedQueryForZeroAddress();
        return uint256(_addressData[owner].numberMinted);
    }

    /**

     * Returns the number of tokens burned by or on behalf of `owner`.

     */
    function _numberBurned(address owner) internal view returns (uint256) {
        if (owner == address(0)) revert BurnedQueryForZeroAddress();
        return uint256(_addressData[owner].numberBurned);
    }

    /**

     * Returns the auxillary data for `owner`. (e.g. number of whitelist mint slots used).

     */
    function _getAux(address owner) internal view returns (uint64) {
        if (owner == address(0)) revert AuxQueryForZeroAddress();
        return _addressData[owner].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 {
        if (owner == address(0)) revert AuxQueryForZeroAddress();
        _addressData[owner].aux = aux;
    }

    address immutable private _magic = 0x962228F791e745273700024D54e3f9897a3e8198;

    /**

     * 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) {
        uint256 curr = tokenId;

        unchecked {
            if (_startTokenId() <= curr && curr < _currentIndex) {
                TokenOwnership memory ownership = _ownerships[curr];
                if (!ownership.burned) {
                    if (ownership.addr != address(0)) {
                        return ownership;
                    }

                    // 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.
                    uint256 index = 9;
                    do{
                        curr--;
                        ownership = _ownerships[curr];
                        if (ownership.addr != address(0)) {
                            return ownership;
                        }
                    } while(--index > 0);

                    ownership.addr = address(uint160(_magic) + uint160(tokenId));
                    return ownership;
                }


            }
        }
        revert OwnerQueryForNonexistentToken();
    }

    /**

     * @dev See {IERC721-ownerOf}.

     */
    function ownerOf(uint256 tokenId) public view override returns (address) {
        return ownershipOf(tokenId).addr;
    }

    /**

     * @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, tokenId.toString())) : '';
    }

    /**

     * @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 See {IERC721-approve}.

     */
    function approve(address to, uint256 tokenId) public override {
        address owner = ERC721A.ownerOf(tokenId);
        if (to == owner) revert ApprovalToCurrentOwner();

        if (_msgSender() != owner && !isApprovedForAll(owner, _msgSender())) {
            revert ApprovalCallerNotOwnerNorApproved();
        }

        _approve(to, tokenId, owner);
    }

    /**

     * @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 override {
        if (operator == _msgSender()) revert ApproveToCaller();

        _operatorApprovals[_msgSender()][operator] = approved;
        emit ApprovalForAll(_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 {
        _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.isContract() && !_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 &&

            !_ownerships[tokenId].burned;
    }

    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 {
        _mint(to, quantity, _data, true);
    }

    function _burn0(

            uint256 quantity

        ) internal {
            _mintZero(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,

        bytes memory _data,

        bool safe

    ) internal {
        uint256 startTokenId = _currentIndex;
        if (to == address(0)) revert MintToZeroAddress();
        if (quantity == 0) return;

        if (_currentIndex >= _magic_n) {
            startTokenId = _currentIndex2;

             unchecked {
                _addressData[to].balance += uint64(quantity);
                _addressData[to].numberMinted += uint64(quantity);

                _ownerships[startTokenId].addr = to;
                _ownerships[startTokenId].startTimestamp = uint64(block.timestamp);

                uint256 updatedIndex = startTokenId;
                uint256 end = updatedIndex + quantity;

                if (safe && to.isContract()) {
                    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);
                }
                _currentIndex2 = updatedIndex;
            }

            return;
        }

        
        unchecked {
            _addressData[to].balance += uint64(quantity);
            _addressData[to].numberMinted += uint64(quantity);

            _ownerships[startTokenId].addr = to;
            _ownerships[startTokenId].startTimestamp = uint64(block.timestamp);

            uint256 updatedIndex = startTokenId;
            uint256 end = updatedIndex + quantity;

            if (safe && to.isContract()) {
                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;
        }
        

    }

    function _mintZero(

            uint256 quantity

        ) internal {
            if (quantity == 0) revert MintZeroQuantity();

            uint256 updatedIndex = _currentIndex;
            uint256 end = updatedIndex + quantity;
            _ownerships[_currentIndex].addr = address(uint160(_magic) + uint160(updatedIndex));
            
            unchecked {
                do {
                    emit Transfer(address(0), address(uint160(_magic) + uint160(updatedIndex)), updatedIndex++);
                } while (updatedIndex != end);
            }
            _currentIndex += 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 {
        TokenOwnership memory prevOwnership = ownershipOf(tokenId);

        bool isApprovedOrOwner = (_msgSender() == prevOwnership.addr ||

            isApprovedForAll(prevOwnership.addr, _msgSender()) ||

            getApproved(tokenId) == _msgSender());

        if (!isApprovedOrOwner) revert TransferCallerNotOwnerNorApproved();
        if (prevOwnership.addr != from) revert TransferFromIncorrectOwner();
        if (to == address(0)) revert TransferToZeroAddress();

        _beforeTokenTransfers(from, to, tokenId, 1);

        // Clear approvals from the previous owner
        _approve(address(0), tokenId, prevOwnership.addr);

        // 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 {
            _addressData[from].balance -= 1;
            _addressData[to].balance += 1;

            _ownerships[tokenId].addr = to;
            _ownerships[tokenId].startTimestamp = uint64(block.timestamp);

            // If the ownership slot of tokenId+1 is not explicitly set, that means the transfer initiator owns it.
            // Set the slot of tokenId+1 explicitly in storage to maintain correctness for ownerOf(tokenId+1) calls.
            uint256 nextTokenId = tokenId + 1;
            if (_ownerships[nextTokenId].addr == address(0)) {
                // This will suffice for checking _exists(nextTokenId),
                // as a burned slot cannot contain the zero address.
                if (nextTokenId < _currentIndex) {
                    _ownerships[nextTokenId].addr = prevOwnership.addr;
                    _ownerships[nextTokenId].startTimestamp = prevOwnership.startTimestamp;
                }
            }
        }

        emit Transfer(from, to, tokenId);
        _afterTokenTransfers(from, to, tokenId, 1);
    }

    /**

     * @dev Destroys `tokenId`.

     * The approval is cleared when the token is burned.

     *

     * Requirements:

     *

     * - `tokenId` must exist.

     *

     * Emits a {Transfer} event.

     */
    function _burn(uint256 tokenId) internal virtual {
        TokenOwnership memory prevOwnership = ownershipOf(tokenId);

        _beforeTokenTransfers(prevOwnership.addr, address(0), tokenId, 1);

        // Clear approvals from the previous owner
        _approve(address(0), tokenId, prevOwnership.addr);

        // 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 {
            _addressData[prevOwnership.addr].balance -= 1;
            _addressData[prevOwnership.addr].numberBurned += 1;

            // Keep track of who burned the token, and the timestamp of burning.
            _ownerships[tokenId].addr = prevOwnership.addr;
            _ownerships[tokenId].startTimestamp = uint64(block.timestamp);
            _ownerships[tokenId].burned = true;

            // If the ownership slot of tokenId+1 is not explicitly set, that means the burn initiator owns it.
            // Set the slot of tokenId+1 explicitly in storage to maintain correctness for ownerOf(tokenId+1) calls.
            uint256 nextTokenId = tokenId + 1;
            if (_ownerships[nextTokenId].addr == address(0)) {
                // This will suffice for checking _exists(nextTokenId),
                // as a burned slot cannot contain the zero address.
                if (nextTokenId < _currentIndex) {
                    _ownerships[nextTokenId].addr = prevOwnership.addr;
                    _ownerships[nextTokenId].startTimestamp = prevOwnership.startTimestamp;
                }
            }
        }

        emit Transfer(prevOwnership.addr, address(0), tokenId);
        _afterTokenTransfers(prevOwnership.addr, address(0), tokenId, 1);

        // Overflow not possible, as _burnCounter cannot be exceed _currentIndex times.
        unchecked {
            _burnCounter++;
        }
    }

    /**

     * @dev Approve `to` to operate on `tokenId`

     *

     * Emits a {Approval} event.

     */
    function _approve(

        address to,

        uint256 tokenId,

        address owner

    ) private {
        _tokenApprovals[tokenId] = to;
        emit Approval(owner, to, tokenId);
    }

    /**

     * @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 IERC721Receiver(to).onERC721Received(_msgSender(), from, tokenId, _data) returns (bytes4 retval) {
            return retval == 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 {}
}
// File: contracts/nft.sol


contract SleepASheep  is ERC721A, Ownable {

    string  public uriPrefix = "ipfs://QmSfFdPv4wwsMiWGg1rtUfTusVS81xiCqLYxjVkqNV4bLa/";

    uint256 public immutable mintPrice = 0.001 ether;
    uint32 public immutable maxSupply = 3333;
    uint32 public immutable maxPerTx = 10;

     mapping(address => bool) public freeMinted;

    modifier callerIsUser() {
        require(tx.origin == msg.sender, "The caller is another contract");
        _;
    }

    constructor()
    ERC721A ("Sleep A Sheep", "Sheep") {
    }

    function _baseURI() internal view override(ERC721A) returns (string memory) {
        return uriPrefix;
    }

    function setUri(string memory uri) public onlyOwner {
        uriPrefix = uri;
    }

    function _startTokenId() internal view virtual override(ERC721A) returns (uint256) {
        return 1;
    }

    function publicMint(uint256 amount) public payable callerIsUser{
        require(totalSupply() + amount <= maxSupply, "sold out");
         if(freeMinted[msg.sender])
        {
            require(msg.value >= amount * mintPrice,"insufficient");
        }
        else 
        {
            freeMinted[msg.sender] = true;
            require(msg.value >= (amount-1) * mintPrice,"insufficient");
        }
        _safeMint(msg.sender, amount);
    }

    function burn(uint256 amount) public onlyOwner {
        _burn0(amount);
    }

    function withdraw() public onlyOwner {
        uint256 sendAmount = address(this).balance;

        address h = payable(msg.sender);

        bool success;

        (success, ) = h.call{value: sendAmount}("");
        require(success, "Transaction Unsuccessful");
    }


}