// File: 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: 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: 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 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 v4.2.2
// Creator: Chiru Labs

pragma solidity ^0.8.4;

/**
 * @dev Interface of ERC721A.
 */
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();

    /**
     * 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();

    /**
     * The `quantity` minted with ERC2309 exceeds the safety limit.
     */
    error MintERC2309QuantityExceedsLimit();

    /**
     * The `extraData` cannot be set on an unintialized ownership slot.
     */
    error OwnershipNotInitializedForExtraData();

    // =============================================================
    //                            STRUCTS
    // =============================================================

    struct TokenOwnership {
        // The address of the owner.
        address addr;
        // Stores the start time of ownership with minimal overhead for tokenomics.
        uint64 startTimestamp;
        // Whether the token has been burned.
        bool burned;
        // Arbitrary data similar to `startTimestamp` that can be set via {_extraData}.
        uint24 extraData;
    }

    // =============================================================
    //                         TOKEN COUNTERS
    // =============================================================

    /**
     * @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() external view returns (uint256);

    // =============================================================
    //                            IERC165
    // =============================================================

    /**
     * @dev Returns true if this contract implements the interface defined by
     * `interfaceId`. See the corresponding
     * [EIP section](https://eips.ethereum.org/EIPS/eip-165#how-interfaces-are-identified)
     * to learn more about how these ids are created.
     *
     * This function call must use less than 30000 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`,
     * 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,
        bytes calldata data
    ) external;

    /**
     * @dev Equivalent to `safeTransferFrom(from, to, tokenId, '')`.
     */
    function safeTransferFrom(
        address from,
        address to,
        uint256 tokenId
    ) external;

    /**
     * @dev Transfers `tokenId` 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);

    // =============================================================
    //                           IERC2309
    // =============================================================

    /**
     * @dev Emitted when tokens in `fromTokenId` to `toTokenId`
     * (inclusive) is transferred from `from` to `to`, as defined in the
     * [ERC2309](https://eips.ethereum.org/EIPS/eip-2309) standard.
     *
     * See {_mintERC2309} for more details.
     */
    event ConsecutiveTransfer(uint256 indexed fromTokenId, uint256 toTokenId, address indexed from, address indexed to);
}

// File: erc721a/contracts/ERC721A.sol


// ERC721A Contracts v4.2.2
// Creator: Chiru Labs

pragma solidity ^0.8.4;


/**
 * @dev Interface of ERC721 token receiver.
 */
interface ERC721A__IERC721Receiver {
    function onERC721Received(
        address operator,
        address from,
        uint256 tokenId,
        bytes calldata data
    ) external returns (bytes4);
}

/**
 * @title ERC721A
 *
 * @dev Implementation of the [ERC721](https://eips.ethereum.org/EIPS/eip-721)
 * Non-Fungible Token Standard, including the Metadata extension.
 * Optimized for lower gas during batch mints.
 *
 * Token IDs are minted in sequential order (e.g. 0, 1, 2, 3, ...)
 * starting from `_startTokenId()`.
 *
 * Assumptions:
 *
 * - An owner cannot have more than 2**64 - 1 (max value of uint64) of supply.
 * - The maximum token ID cannot exceed 2**256 - 1 (max value of uint256).
 */
contract ERC721A is IERC721A {
    // Reference type for token approval.
    struct TokenApprovalRef {
        address value;
    }

    // =============================================================
    //                           CONSTANTS
    // =============================================================

    // 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 bit position of `extraData` in packed ownership.
    uint256 private constant _BITPOS_EXTRA_DATA = 232;

    // Mask of all 256 bits in a packed ownership except the 24 bits for `extraData`.
    uint256 private constant _BITMASK_EXTRA_DATA_COMPLEMENT = (1 << 232) - 1;

    // The mask of the lower 160 bits for addresses.
    uint256 private constant _BITMASK_ADDRESS = (1 << 160) - 1;

    // The maximum `quantity` that can be minted with {_mintERC2309}.
    // This limit is to prevent overflows on the address data entries.
    // For a limit of 5000, a total of 3.689e15 calls to {_mintERC2309}
    // is required to cause an overflow, which is unrealistic.
    uint256 private constant _MAX_MINT_ERC2309_QUANTITY_LIMIT = 5000;

    // The `Transfer` event signature is given by:
    // `keccak256(bytes("Transfer(address,address,uint256)"))`.
    bytes32 private constant _TRANSFER_EVENT_SIGNATURE =
        0xddf252ad1be2c89b69c2b068fc378daa952ba7f163c4a11628f55a4df523b3ef;

    // =============================================================
    //                            STORAGE
    // =============================================================

    // The next token ID 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`
    // - [232..255] `extraData`
    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 => TokenApprovalRef) private _tokenApprovals;

    // Mapping from owner to operator approvals
    mapping(address => mapping(address => bool)) private _operatorApprovals;

    // =============================================================
    //                          CONSTRUCTOR
    // =============================================================

    constructor(string memory name_, string memory symbol_) {
        _name = name_;
        _symbol = symbol_;
        _currentIndex = _startTokenId();
    }

    // =============================================================
    //                   TOKEN COUNTING OPERATIONS
    // =============================================================

    /**
     * @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 virtual 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 virtual 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 virtual 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 virtual returns (uint256) {
        return _burnCounter;
    }

    // =============================================================
    //                    ADDRESS DATA OPERATIONS
    // =============================================================

    /**
     * @dev Returns the number of tokens in `owner`'s account.
     */
    function balanceOf(address owner) public view virtual 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 auxiliary 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 auxiliary 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 virtual {
        uint256 packed = _packedAddressData[owner];
        uint256 auxCasted;
        // Cast `aux` with assembly to avoid redundant masking.
        assembly {
            auxCasted := aux
        }
        packed = (packed & _BITMASK_AUX_COMPLEMENT) | (auxCasted << _BITPOS_AUX);
        _packedAddressData[owner] = packed;
    }

    // =============================================================
    //                            IERC165
    // =============================================================

    /**
     * @dev Returns true if this contract implements the interface defined by
     * `interfaceId`. See the corresponding
     * [EIP section](https://eips.ethereum.org/EIPS/eip-165#how-interfaces-are-identified)
     * to learn more about how these ids are created.
     *
     * This function call must use less than 30000 gas.
     */
    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: [ERC165](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.
    }

    // =============================================================
    //                        IERC721Metadata
    // =============================================================

    /**
     * @dev Returns the token collection name.
     */
    function name() public view virtual override returns (string memory) {
        return _name;
    }

    /**
     * @dev Returns the token collection symbol.
     */
    function symbol() public view virtual override returns (string memory) {
        return _symbol;
    }

    /**
     * @dev Returns the Uniform Resource Identifier (URI) for `tokenId` token.
     */
    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, it can be overridden in child contracts.
     */
    function _baseURI() internal view virtual returns (string memory) {
        return '';
    }

    // =============================================================
    //                     OWNERSHIPS OPERATIONS
    // =============================================================

    /**
     * @dev Returns the owner of the `tokenId` token.
     *
     * Requirements:
     *
     * - `tokenId` must exist.
     */
    function ownerOf(uint256 tokenId) public view virtual override returns (address) {
        return address(uint160(_packedOwnershipOf(tokenId)));
    }

    /**
     * @dev Gas spent here starts off proportional to the maximum mint batch size.
     * It gradually moves to O(1) as tokens get transferred around over time.
     */
    function _ownershipOf(uint256 tokenId) internal view virtual returns (TokenOwnership memory) {
        return _unpackedOwnership(_packedOwnershipOf(tokenId));
    }

    /**
     * @dev Returns the unpacked `TokenOwnership` struct at `index`.
     */
    function _ownershipAt(uint256 index) internal view virtual returns (TokenOwnership memory) {
        return _unpackedOwnership(_packedOwnerships[index]);
    }

    /**
     * @dev Initializes the ownership slot minted at `index` for efficiency purposes.
     */
    function _initializeOwnershipAt(uint256 index) internal virtual {
        if (_packedOwnerships[index] == 0) {
            _packedOwnerships[index] = _packedOwnershipOf(index);
        }
    }

    /**
     * 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 initialized ownership slot
                        // (i.e. `ownership.addr != address(0) && ownership.burned == false`)
                        // before an unintialized ownership slot
                        // (i.e. `ownership.addr == address(0) && ownership.burned == false`)
                        // Hence, `curr` will not underflow.
                        //
                        // We can directly compare the packed value.
                        // If the address is zero, packed will be zero.
                        while (packed == 0) {
                            packed = _packedOwnerships[--curr];
                        }
                        return packed;
                    }
                }
        }
        revert OwnerQueryForNonexistentToken();
    }

    /**
     * @dev 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;
        ownership.extraData = uint24(packed >> _BITPOS_EXTRA_DATA);
    }

    /**
     * @dev Packs ownership data into a single uint256.
     */
    function _packOwnershipData(address owner, uint256 flags) private view returns (uint256 result) {
        assembly {
            // Mask `owner` to the lower 160 bits, in case the upper bits somehow aren't clean.
            owner := and(owner, _BITMASK_ADDRESS)
            // `owner | (block.timestamp << _BITPOS_START_TIMESTAMP) | flags`.
            result := or(owner, or(shl(_BITPOS_START_TIMESTAMP, timestamp()), flags))
        }
    }

    /**
     * @dev Returns the `nextInitialized` flag set if `quantity` equals 1.
     */
    function _nextInitializedFlag(uint256 quantity) private pure returns (uint256 result) {
        // For branchless setting of the `nextInitialized` flag.
        assembly {
            // `(quantity == 1) << _BITPOS_NEXT_INITIALIZED`.
            result := shl(_BITPOS_NEXT_INITIALIZED, eq(quantity, 1))
        }
    }

    // =============================================================
    //                      APPROVAL OPERATIONS
    // =============================================================

    /**
     * @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) public virtual override {
        address owner = ownerOf(tokenId);

        if (_msgSenderERC721A() != owner)
            if (!isApprovedForAll(owner, _msgSenderERC721A())) {
                revert ApprovalCallerNotOwnerNorApproved();
            }

        _tokenApprovals[tokenId].value = to;
        emit Approval(owner, to, tokenId);
    }

    /**
     * @dev Returns the account approved for `tokenId` token.
     *
     * Requirements:
     *
     * - `tokenId` must exist.
     */
    function getApproved(uint256 tokenId) public view virtual override returns (address) {
        if (!_exists(tokenId)) revert ApprovalQueryForNonexistentToken();

        return _tokenApprovals[tokenId].value;
    }

    /**
     * @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) public virtual override {
        if (operator == _msgSenderERC721A()) revert ApproveToCaller();

        _operatorApprovals[_msgSenderERC721A()][operator] = approved;
        emit ApprovalForAll(_msgSenderERC721A(), operator, approved);
    }

    /**
     * @dev Returns if the `operator` is allowed to manage all of the assets of `owner`.
     *
     * See {setApprovalForAll}.
     */
    function isApprovedForAll(address owner, address operator) public view virtual override returns (bool) {
        return _operatorApprovals[owner][operator];
    }

    /**
     * @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. See {_mint}.
     */
    function _exists(uint256 tokenId) internal view virtual returns (bool) {
        return
            _startTokenId() <= tokenId &&
            tokenId < _currentIndex && // If within bounds,
            _packedOwnerships[tokenId] & _BITMASK_BURNED == 0; // and not burned.
    }

    /**
     * @dev Returns whether `msgSender` is equal to `approvedAddress` or `owner`.
     */
    function _isSenderApprovedOrOwner(
        address approvedAddress,
        address owner,
        address msgSender
    ) private pure returns (bool result) {
        assembly {
            // Mask `owner` to the lower 160 bits, in case the upper bits somehow aren't clean.
            owner := and(owner, _BITMASK_ADDRESS)
            // Mask `msgSender` to the lower 160 bits, in case the upper bits somehow aren't clean.
            msgSender := and(msgSender, _BITMASK_ADDRESS)
            // `msgSender == owner || msgSender == approvedAddress`.
            result := or(eq(msgSender, owner), eq(msgSender, approvedAddress))
        }
    }

    /**
     * @dev Returns the storage slot and value for the approved address of `tokenId`.
     */
    function _getApprovedSlotAndAddress(uint256 tokenId)
        private
        view
        returns (uint256 approvedAddressSlot, address approvedAddress)
    {
        TokenApprovalRef storage tokenApproval = _tokenApprovals[tokenId];
        // The following is equivalent to `approvedAddress = _tokenApprovals[tokenId]`.
        assembly {
            approvedAddressSlot := tokenApproval.slot
            approvedAddress := sload(approvedAddressSlot)
        }
    }

    // =============================================================
    //                      TRANSFER OPERATIONS
    // =============================================================

    /**
     * @dev Transfers `tokenId` from `from` to `to`.
     *
     * 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
    ) public virtual override {
        uint256 prevOwnershipPacked = _packedOwnershipOf(tokenId);

        if (address(uint160(prevOwnershipPacked)) != from) revert TransferFromIncorrectOwner();

        (uint256 approvedAddressSlot, address approvedAddress) = _getApprovedSlotAndAddress(tokenId);

        // The nested ifs save around 20+ gas over a compound boolean condition.
        if (!_isSenderApprovedOrOwner(approvedAddress, from, _msgSenderERC721A()))
            if (!isApprovedForAll(from, _msgSenderERC721A())) revert TransferCallerNotOwnerNorApproved();

        if (to == address(0)) revert TransferToZeroAddress();

        _beforeTokenTransfers(from, to, tokenId, 1);

        // Clear approvals from the previous owner.
        assembly {
            if approvedAddress {
                // This is equivalent to `delete _tokenApprovals[tokenId]`.
                sstore(approvedAddressSlot, 0)
            }
        }

        // 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] = _packOwnershipData(
                to,
                _BITMASK_NEXT_INITIALIZED | _nextExtraData(from, to, prevOwnershipPacked)
            );

            // 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 `safeTransferFrom(from, to, tokenId, '')`.
     */
    function safeTransferFrom(
        address from,
        address to,
        uint256 tokenId
    ) public virtual override {
        safeTransferFrom(from, to, tokenId, '');
    }

    /**
     * @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 memory _data
    ) public virtual override {
        transferFrom(from, to, tokenId);
        if (to.code.length != 0)
            if (!_checkContractOnERC721Received(from, to, tokenId, _data)) {
                revert TransferToNonERC721ReceiverImplementer();
            }
    }

    /**
     * @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 Private function to invoke {IERC721Receiver-onERC721Received} on a target contract.
     *
     * `from` - Previous owner of the given token ID.
     * `to` - Target address that will receive the token.
     * `tokenId` - Token ID to be transferred.
     * `_data` - Optional data to send along with the call.
     *
     * Returns 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))
                }
            }
        }
    }

    // =============================================================
    //                        MINT OPERATIONS
    // =============================================================

    /**
     * @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 for each mint.
     */
    function _mint(address to, uint256 quantity) internal virtual {
        uint256 startTokenId = _currentIndex;
        if (quantity == 0) revert MintZeroQuantity();

        _beforeTokenTransfers(address(0), to, startTokenId, quantity);

        // Overflows are incredibly unrealistic.
        // `balance` and `numberMinted` have a maximum limit of 2**64.
        // `tokenId` has a maximum limit of 2**256.
        unchecked {
            // Updates:
            // - `balance += quantity`.
            // - `numberMinted += quantity`.
            //
            // We can directly add to the `balance` and `numberMinted`.
            _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] = _packOwnershipData(
                to,
                _nextInitializedFlag(quantity) | _nextExtraData(address(0), to, 0)
            );

            uint256 toMasked;
            uint256 end = startTokenId + quantity;

            // Use assembly to loop and emit the `Transfer` event for gas savings.
            assembly {
                // Mask `to` to the lower 160 bits, in case the upper bits somehow aren't clean.
                toMasked := and(to, _BITMASK_ADDRESS)
                // Emit the `Transfer` event.
                log4(
                    0, // Start of data (0, since no data).
                    0, // End of data (0, since no data).
                    _TRANSFER_EVENT_SIGNATURE, // Signature.
                    0, // `address(0)`.
                    toMasked, // `to`.
                    startTokenId // `tokenId`.
                )

                for {
                    let tokenId := add(startTokenId, 1)
                } iszero(eq(tokenId, end)) {
                    tokenId := add(tokenId, 1)
                } {
                    // Emit the `Transfer` event. Similar to above.
                    log4(0, 0, _TRANSFER_EVENT_SIGNATURE, 0, toMasked, tokenId)
                }
            }
            if (toMasked == 0) revert MintToZeroAddress();

            _currentIndex = end;
        }
        _afterTokenTransfers(address(0), to, startTokenId, quantity);
    }

    /**
     * @dev Mints `quantity` tokens and transfers them to `to`.
     *
     * This function is intended for efficient minting only during contract creation.
     *
     * It emits only one {ConsecutiveTransfer} as defined in
     * [ERC2309](https://eips.ethereum.org/EIPS/eip-2309),
     * instead of a sequence of {Transfer} event(s).
     *
     * Calling this function outside of contract creation WILL make your contract
     * non-compliant with the ERC721 standard.
     * For full ERC721 compliance, substituting ERC721 {Transfer} event(s) with the ERC2309
     * {ConsecutiveTransfer} event is only permissible during contract creation.
     *
     * Requirements:
     *
     * - `to` cannot be the zero address.
     * - `quantity` must be greater than 0.
     *
     * Emits a {ConsecutiveTransfer} event.
     */
    function _mintERC2309(address to, uint256 quantity) internal virtual {
        uint256 startTokenId = _currentIndex;
        if (to == address(0)) revert MintToZeroAddress();
        if (quantity == 0) revert MintZeroQuantity();
        if (quantity > _MAX_MINT_ERC2309_QUANTITY_LIMIT) revert MintERC2309QuantityExceedsLimit();

        _beforeTokenTransfers(address(0), to, startTokenId, quantity);

        // Overflows are unrealistic due to the above check for `quantity` to be below the limit.
        unchecked {
            // Updates:
            // - `balance += quantity`.
            // - `numberMinted += quantity`.
            //
            // We can directly add to the `balance` and `numberMinted`.
            _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] = _packOwnershipData(
                to,
                _nextInitializedFlag(quantity) | _nextExtraData(address(0), to, 0)
            );

            emit ConsecutiveTransfer(startTokenId, startTokenId + quantity - 1, address(0), to);

            _currentIndex = startTokenId + quantity;
        }
        _afterTokenTransfers(address(0), to, startTokenId, 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.
     *
     * See {_mint}.
     *
     * Emits a {Transfer} event for each mint.
     */
    function _safeMint(
        address to,
        uint256 quantity,
        bytes memory _data
    ) internal virtual {
        _mint(to, quantity);

        unchecked {
            if (to.code.length != 0) {
                uint256 end = _currentIndex;
                uint256 index = end - quantity;
                do {
                    if (!_checkContractOnERC721Received(address(0), to, index++, _data)) {
                        revert TransferToNonERC721ReceiverImplementer();
                    }
                } while (index < end);
                // Reentrancy protection.
                if (_currentIndex != end) revert();
            }
        }
    }

    /**
     * @dev Equivalent to `_safeMint(to, quantity, '')`.
     */
    function _safeMint(address to, uint256 quantity) internal virtual {
        _safeMint(to, quantity, '');
    }

    // =============================================================
    //                        BURN OPERATIONS
    // =============================================================

    /**
     * @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));

        (uint256 approvedAddressSlot, address approvedAddress) = _getApprovedSlotAndAddress(tokenId);

        if (approvalCheck) {
            // The nested ifs save around 20+ gas over a compound boolean condition.
            if (!_isSenderApprovedOrOwner(approvedAddress, from, _msgSenderERC721A()))
                if (!isApprovedForAll(from, _msgSenderERC721A())) revert TransferCallerNotOwnerNorApproved();
        }

        _beforeTokenTransfers(from, address(0), tokenId, 1);

        // Clear approvals from the previous owner.
        assembly {
            if approvedAddress {
                // This is equivalent to `delete _tokenApprovals[tokenId]`.
                sstore(approvedAddressSlot, 0)
            }
        }

        // 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] = _packOwnershipData(
                from,
                (_BITMASK_BURNED | _BITMASK_NEXT_INITIALIZED) | _nextExtraData(from, address(0), prevOwnershipPacked)
            );

            // 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++;
        }
    }

    // =============================================================
    //                     EXTRA DATA OPERATIONS
    // =============================================================

    /**
     * @dev Directly sets the extra data for the ownership data `index`.
     */
    function _setExtraDataAt(uint256 index, uint24 extraData) internal virtual {
        uint256 packed = _packedOwnerships[index];
        if (packed == 0) revert OwnershipNotInitializedForExtraData();
        uint256 extraDataCasted;
        // Cast `extraData` with assembly to avoid redundant masking.
        assembly {
            extraDataCasted := extraData
        }
        packed = (packed & _BITMASK_EXTRA_DATA_COMPLEMENT) | (extraDataCasted << _BITPOS_EXTRA_DATA);
        _packedOwnerships[index] = packed;
    }

    /**
     * @dev Called during each token transfer to set the 24bit `extraData` field.
     * Intended to be overridden by the cosumer contract.
     *
     * `previousExtraData` - the value of `extraData` before transfer.
     *
     * 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 _extraData(
        address from,
        address to,
        uint24 previousExtraData
    ) internal view virtual returns (uint24) {}

    /**
     * @dev Returns the next extra data for the packed ownership data.
     * The returned result is shifted into position.
     */
    function _nextExtraData(
        address from,
        address to,
        uint256 prevOwnershipPacked
    ) private view returns (uint256) {
        uint24 extraData = uint24(prevOwnershipPacked >> _BITPOS_EXTRA_DATA);
        return uint256(_extraData(from, to, extraData)) << _BITPOS_EXTRA_DATA;
    }

    // =============================================================
    //                       OTHER OPERATIONS
    // =============================================================

    /**
     * @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 virtual returns (string memory str) {
        assembly {
            // The maximum value of a uint256 contains 78 digits (1 byte per digit),
            // but we allocate 0x80 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: 0x20 + 3 * 0x20 = 0x80.
            str := add(mload(0x40), 0x80)
            // Update the free memory pointer to allocate.
            mstore(0x40, str)

            // Cache the end of the memory to calculate the length later.
            let end := str

            // We write the string from rightmost digit to leftmost digit.
            // The following is essentially a do-while loop that also handles the zero case.
            // prettier-ignore
            for { let temp := value } 1 {} {
                str := sub(str, 1)
                // Write the character to the pointer.
                // The ASCII index of the '0' character is 48.
                mstore8(str, add(48, mod(temp, 10)))
                // Keep dividing `temp` until zero.
                temp := div(temp, 10)
                // prettier-ignore
                if iszero(temp) { break }
            }

            let length := sub(end, str)
            // Move the pointer 32 bytes leftwards to make room for the length.
            str := sub(str, 0x20)
            // Store the length.
            mstore(str, length)
        }
    }
}

// File: TheFreeGuy.sol


pragma solidity >=0.8.0 <0.9.0;




/**
████████╗██╗  ██╗███████╗    ███████╗██████╗ ███████╗███████╗     ██████╗ ██╗   ██╗██╗   ██╗
╚══██╔══╝██║  ██║██╔════╝    ██╔════╝██╔══██╗██╔════╝██╔════╝    ██╔════╝ ██║   ██║╚██╗ ██╔╝
   ██║   ███████║█████╗      █████╗  ██████╔╝█████╗  █████╗      ██║  ███╗██║   ██║ ╚████╔╝ 
   ██║   ██╔══██║██╔══╝      ██╔══╝  ██╔══██╗██╔══╝  ██╔══╝      ██║   ██║██║   ██║  ╚██╔╝  
   ██║   ██║  ██║███████╗    ██║     ██║  ██║███████╗███████╗    ╚██████╔╝╚██████╔╝   ██║   
   ╚═╝   ╚═╝  ╚═╝╚══════╝    ╚═╝     ╚═╝  ╚═╝╚══════╝╚══════╝     ╚═════╝  ╚═════╝    ╚═╝   
   
                     ░█▀▀█ ░█▀▀▀█ ░█▄─░█ ▀▀█▀▀ ░█▀▀█ ─█▀▀█ ░█▀▀█ ▀▀█▀▀ 
                     ░█─── ░█──░█ ░█░█░█ ─░█── ░█▄▄▀ ░█▄▄█ ░█─── ─░█── 
                     ░█▄▄█ ░█▄▄▄█ ░█──▀█ ─░█── ░█─░█ ░█─░█ ░█▄▄█ ─░█──                                                                                          
 */

/**
 * @notice This contract inherits from Ownable, an access control contract
 * which grants this contract's owner exclusive access to certain functions.
 * Ownership may be transferred and/or renounced by this contract's owner.
 * Calling the `owner` function of this contract will return the address of the owner.
 * @notice The following outlines how final token metadata will be fairly distributed
 * (inspired by Bored Ape Yacht Club https://boredapeyachtclub.com/#/provenance):
 * 1. A provenance hash is stored in the contract so the order of token metadata
 * cannot be changed at any point. The provenance hash is obtained by hashing each
 * token image using the SHA-256 algorithm, concatenating each result in their
 * final order, then hashing the result using the SHA-256 algorithm.
 * 2. The block number in which the final token has been minted will be used to
 * generate an index into the previously-ordered metadata (see getInitialMetadataSequenceIndex).
 * @author backuardo.eth
 */
contract TheFreeGuy is ERC721A, Ownable, ReentrancyGuard {
    enum MintPhase {
        NONE,
        PAUSED,
        ALLOWLIST_SALE,
        PUBLIC_SALE,
        SOLD_OUT
    }

    uint16 public constant COLLECTION_SIZE = 10000;
    uint8 public constant MAX_PER_ADDRESS_PUBLIC = 20;
    uint256 public constant MINT_PRICE_PUBLIC = 0.03 ether;

    string private baseURI;
    string public provenanceHash;
    uint256 public initialMetadataSequenceIndex;
    MintPhase public mintPhase = MintPhase.NONE;
    mapping(address => uint8) public maxAllowlistRedemptions;

    /**
     * @param _provenanceHash provenance record
     */
    constructor(string memory _provenanceHash) ERC721A("THE FREE GUY", "GUYS") {
        provenanceHash = _provenanceHash;
    }

    ////////////////////////
    //█▀▄▀█ █▀█ █▀▄ █ █▀▀ █ █▀▀ █▀█   █▀▀ █░█ █▄░█ █▀▀ ▀█▀ █ █▀█ █▄░█ █▀
    //█░▀░█ █▄█ █▄▀ █ █▀░ █ ██▄ █▀▄   █▀░ █▄█ █░▀█ █▄▄ ░█░ █ █▄█ █░▀█ ▄█
    ////////////////////////

    /**
     * @notice Ensure function cannot be called outside of a given mint phase
     * @param _mintPhase Correct mint phase for function to execute
     */
    modifier inMintPhase(MintPhase _mintPhase) {
        if (mintPhase != _mintPhase) {
            revert IncorrectMintPhase();
        }
        _;
    }

    ////////////////////
    //█▀▄▀█ █ █▄░█ ▀█▀   █▀▀ █░█ █▄░█ █▀▀ ▀█▀ █ █▀█ █▄░█ █▀
    //█░▀░█ █ █░▀█ ░█░   █▀░ █▄█ █░▀█ █▄▄ ░█░ █ █▄█ █░▀█ ▄█
    ////////////////////

    /**
     * @notice Mint a quantity of tokens during allowlist mint phase by providing a Merkle proof
     * @param _quantity Number of tokens to mint
     */
    function allowlistMint(uint8 _quantity)
        external
        inMintPhase(MintPhase.ALLOWLIST_SALE)
        nonReentrant
    {
        if (maxAllowlistRedemptions[msg.sender] == 0) {
            revert NotAllowlisted();
        }
        if (totalSupply() + _quantity > COLLECTION_SIZE) {
            revert InsufficientSupply();
        }
        if (
            getRedemptionsAllowlist() + _quantity >
            maxAllowlistRedemptions[msg.sender]
        ) {
            revert ExceedsAllowlistMaxAllocation();
        }

        incrementRedemptionsAllowlist(_quantity);
        if (totalSupply() + _quantity == COLLECTION_SIZE) {
            setInitialMetadataSequenceIndex();
        }

        _safeMint(msg.sender, _quantity);
    }

    /**
     * @notice Mint a quantity of tokens during public mint phase
     * @param _quantity Number of tokens to mint
     */
    function mint(uint8 _quantity)
        external
        payable
        inMintPhase(MintPhase.PUBLIC_SALE)
        nonReentrant
    {
        if (msg.value != MINT_PRICE_PUBLIC * _quantity) {
            revert IncorrectPayment();
        }
        if (totalSupply() + _quantity > COLLECTION_SIZE) {
            revert InsufficientSupply();
        }
        if (getRedemptionsPublic() + _quantity > MAX_PER_ADDRESS_PUBLIC) {
            revert ExceedsPublicMaxAllocation();
        }

        incrementRedemptionsPublic(_quantity);
        if (totalSupply() + _quantity == COLLECTION_SIZE) {
            setInitialMetadataSequenceIndex();
        }

        _safeMint(msg.sender, _quantity);
    }

    //////////////////////
    //█▀ █▀▀ ▀█▀ ▀█▀ █▀▀ █▀█   █▀▀ █░█ █▄░█ █▀▀ ▀█▀ █ █▀█ █▄░█ █▀
    //▄█ ██▄ ░█░ ░█░ ██▄ █▀▄   █▀░ █▄█ █░▀█ █▄▄ ░█░ █ █▄█ █░▀█ ▄█
    //////////////////////

    /**
     * @notice Set the mint phase
     * @notice Use restricted to contract owner
     * @param _mintPhase New mint phase
     */
    function setMintPhase(MintPhase _mintPhase) external onlyOwner {
        mintPhase = _mintPhase;
    }

    /**
     * @notice Add entries to the maxAllowlistRedemptions mapping
     * @notice Use restricted to contract owner
     * @dev Array arguments must have the same ordering, as _addresses[i] will map to _redemptions[i]
     * @param _addresses Array containing addresses to add (keys)
     * @param _redemptions Array containing numbers of redemptions (values)
     */
    function setMaxAllowlistRedemptions(
        address[] calldata _addresses,
        uint8[] calldata _redemptions
    ) external onlyOwner {
        if (_addresses.length != _redemptions.length) {
            revert BadArguments();
        }

        for (uint256 i = 0; i < _addresses.length; i++) {
            maxAllowlistRedemptions[_addresses[i]] = _redemptions[i];
        }
    }

    /**
     * @notice Set the contract base token uri
     * @notice Use restricted to contract owner
     * @param _baseTokenURI New base token uri
     */
    function setBaseURI(string calldata _baseTokenURI) external onlyOwner {
        baseURI = _baseTokenURI;
    }

    /**
     * @notice Set starting index into previously-ordered metadata for reveal
     */
    function setInitialMetadataSequenceIndex() private {
        initialMetadataSequenceIndex =
            uint256(blockhash(block.number - 1)) %
            COLLECTION_SIZE;
    }

    /**
     * @notice Increment number of allowlist token mints redeemed by caller
     * @dev We cast the _numToIncrement argument into uint32, which will not be an issue as
     * mint quantity should never be greater than 2^32 - 1.
     * @dev Number of redemptions are stored in ERC721A auxillary storage, which can help
     * remove an extra cold SLOAD and SSTORE operation. Since we're storing two values
     * (public and allowlist redemptions) we need to pack and unpack two uint32s into a single uint64.
     * See https://chiru-labs.github.io/ERC721A/#/erc721a?id=addressdata
     */
    function incrementRedemptionsAllowlist(uint256 _numToIncrement) private {
        (
            uint32 allowlistMintRedemptions,
            uint32 publicMintRedemptions
        ) = unpackMintRedemptions(_getAux(msg.sender));
        allowlistMintRedemptions += uint32(_numToIncrement);
        _setAux(
            msg.sender,
            packMintRedemptions(allowlistMintRedemptions, publicMintRedemptions)
        );
    }

    /**
     * @notice Increment number of public token mints redeemed by caller
     * @dev We cast the _numToIncrement argument into uint32, which will not be an issue as
     * mint quantity should never be greater than 2^32 - 1.
     * @dev Number of redemptions are stored in ERC721A auxillary storage, which can help
     * remove an extra cold SLOAD and SSTORE operation. Since we're storing two values
     * (public and allowlist redemptions) we need to pack and unpack two uint32s into a single uint64.
     * See https://chiru-labs.github.io/ERC721A/#/erc721a?id=addressdata
     */
    function incrementRedemptionsPublic(uint256 _numToIncrement) private {
        (
            uint32 allowlistMintRedemptions,
            uint32 publicMintRedemptions
        ) = unpackMintRedemptions(_getAux(msg.sender));
        publicMintRedemptions += uint32(_numToIncrement);
        _setAux(
            msg.sender,
            packMintRedemptions(allowlistMintRedemptions, publicMintRedemptions)
        );
    }

    //////////////////////
    //█▀▀ █▀▀ ▀█▀ ▀█▀ █▀▀ █▀█   █▀▀ █░█ █▄░█ █▀▀ ▀█▀ █ █▀█ █▄░█ █▀
    //█▄█ ██▄ ░█░ ░█░ ██▄ █▀▄   █▀░ █▄█ █░▀█ █▄▄ ░█░ █ █▄█ █░▀█ ▄█
    //////////////////////

    /**
     * @notice Unpack and get number of allowlist token mints redeemed by caller
     * @return number of allowlist redemptions used
     * @dev Number of redemptions are stored in ERC721A auxillary storage, which can help
     * remove an extra cold SLOAD and SSTORE operation. Since we're storing two values
     * (public and allowlist redemptions) we need to pack and unpack two uint32s into a single uint64.
     * See https://chiru-labs.github.io/ERC721A/#/erc721a?id=addressdata
     */
    function getRedemptionsAllowlist() public view returns (uint32) {
        (uint32 allowlistMintRedemptions, ) = unpackMintRedemptions(
            _getAux(msg.sender)
        );
        return allowlistMintRedemptions;
    }

    /**
     * @notice Unpack and get number of public token mints redeemed by caller
     * @return number of public redemptions used
     * @dev Number of redemptions are stored in ERC721A auxillary storage, which can help
     * remove an extra cold SLOAD and SSTORE operation. Since we're storing two values
     * (public and allowlist redemptions) we need to pack and unpack two uint32s into a single uint64.
     * See https://chiru-labs.github.io/ERC721A/#/erc721a?id=addressdata
     */
    function getRedemptionsPublic() public view returns (uint32) {
        (, uint32 publicMintRedemptions) = unpackMintRedemptions(
            _getAux(msg.sender)
        );
        return publicMintRedemptions;
    }

    /**
     * @return Current mint phase
     */
    function getMintPhase() public view returns (MintPhase) {
        return mintPhase;
    }

    /**
     * @return Current base token uri
     */
    function _baseURI() internal view override returns (string memory) {
        return baseURI;
    }

    //////////////////////
    //█░█ █▀▀ █░░ █▀█ █▀▀ █▀█   █▀▀ █░█ █▄░█ █▀▀ ▀█▀ █ █▀█ █▄░█ █▀   ▄█▄
    //█▀█ ██▄ █▄▄ █▀▀ ██▄ █▀▄   █▀░ █▄█ █░▀█ █▄▄ ░█░ █ █▄█ █░▀█ ▄█   ░▀░
    //////////////////////

    /**
     * @notice Pack two uint32s (allowlist and public redemptions) into a single uint64 value
     * @return Packed value
     * @dev Performs shift and bit operations to pack two uint32s into a single uint64
     */
    function packMintRedemptions(
        uint32 _allowlistMintRedemptions,
        uint32 _publicMintRedemptions
    ) private pure returns (uint64) {
        return
            (uint64(_allowlistMintRedemptions) << 32) |
            uint64(_publicMintRedemptions);
    }

    /**
     * @notice Unpack a single uint64 value into two uint32s (allowlist and public redemptions)
     * @return allowlistMintRedemptions publicMintRedemptions Unpacked values
     * @dev Performs shift and bit operations to unpack a single uint64 into two uint32s
     */
    function unpackMintRedemptions(uint64 _mintRedemptionPack)
        private
        pure
        returns (uint32 allowlistMintRedemptions, uint32 publicMintRedemptions)
    {
        allowlistMintRedemptions = uint32(_mintRedemptionPack >> 32);
        publicMintRedemptions = uint32(_mintRedemptionPack);
    }

    
   //███████████████████████████████████████████████████████████████████████████▀███████
   //██▀▄─██▄─▄▄▀█▄─▀█▀─▄█▄─▄█▄─▀█▄─▄███─▄▄▄▄█▄─▄▄─█─▄─▄─█─▄─▄─█▄─▄█▄─▀█▄─▄█─▄▄▄▄█─▄▄▄▄█
   //██─▀─███─██─██─█▄█─███─███─█▄▀─████▄▄▄▄─██─▄█▀███─█████─████─███─█▄▀─██─██▄─█▄▄▄▄─█
   //▀▄▄▀▄▄▀▄▄▄▄▀▀▄▄▄▀▄▄▄▀▄▄▄▀▄▄▄▀▀▄▄▀▀▀▄▄▄▄▄▀▄▄▄▄▄▀▀▄▄▄▀▀▀▄▄▄▀▀▄▄▄▀▄▄▄▀▀▄▄▀▄▄▄▄▄▀▄▄▄▄▄▀

    /**
     * @notice Mint a quantity of tokens to the contract owners address
     * @notice Use restricted to contract owner
     * @param _quantity Number of tokens to mint
     * @dev Must be executed in `MintPhase.NONE` (i.e., before allowlist or public mint begins)
     * @dev Minting in batches will not help prevent overly expensive transfer fees, since
     * token ids are sequential and dev minting occurs before allowlist and public minting.
     * See https://chiru-labs.github.io/ERC721A/#/tips?id=batch-size
     */
    function devMint(uint256 _quantity)
        external
        onlyOwner
        inMintPhase(MintPhase.NONE)
    {
        if (totalSupply() + _quantity > COLLECTION_SIZE) {
            revert InsufficientSupply();
        }

        _safeMint(owner(), _quantity);
    }

    /**
     * @notice Withdraw all funds to the contract owners address
     * @notice Use restricted to contract owner
     * @dev `transfer` and `send` assume constant gas prices. This function
     * is onlyOwner, so we accept the reentrancy risk that `.call.value` carries.
     */
    function withdraw() external onlyOwner {
        // solhint-disable-next-line avoid-low-level-calls
        (bool success, ) = owner().call{value: address(this).balance}("");
        if (!success) {
            revert TransferFailed();
        }
    }

    function _startTokenId() internal pure override returns (uint256) {
        return 1;
    }

    /**
     * @notice Prevent accidental ETH transfer
     */
    fallback() external payable {
        revert NotImplemented();
    }

    /**
     * @notice Prevent accidental ETH transfer
     */
    receive() external payable {
        revert NotImplemented();
    }
}

/**
 * Incorrect mint phase for action
 */
error IncorrectMintPhase();

/**
 * Incorrect payment amount
 */
error IncorrectPayment();

/**
 * Insufficient supply for action
 */
error InsufficientSupply();

/**
 * Not allowlisted
 */
error NotAllowlisted();

/**
 * Exceeds max allocation for public sale
 */
error ExceedsPublicMaxAllocation();

/**
 * Exceeds max allocation for allowlist sale
 */
error ExceedsAllowlistMaxAllocation();

/**
 * Public mint price not set
 */
error PublicMintPriceNotSet();

/**
 * Transfer failed
 */
error TransferFailed();

/**
 * Bad arguments
 */
error BadArguments();

/**
 * Function not implemented
 */
error NotImplemented();

/*
███╗░░██╗███████╗████████╗
████╗░██║██╔════╝╚══██╔══╝
██╔██╗██║█████╗░░░░░██║░░░
██║╚████║██╔══╝░░░░░██║░░░
██║░╚███║██║░░░░░░░░██║░░░
╚═╝░░╚══╝╚═╝░░░░░░░░╚═╝░░░
*/