// SPDX-License-Identifier: GPL-3.0
// File: @openzeppelin/contracts/security/ReentrancyGuard.sol
// OpenZeppelin Contracts (last updated v4.8.0) (security/ReentrancyGuard.sol)

pragma solidity ^0.8.0;
abstract contract ReentrancyGuard {
    uint256 private constant _NOT_ENTERED = 1;
    uint256 private constant _ENTERED = 2;

    uint256 private _status;

    constructor() {
        _status = _NOT_ENTERED;
    }
    modifier nonReentrant() {
        _nonReentrantBefore();
        _;
        _nonReentrantAfter();
    }
    function _nonReentrantBefore() private {
        
        require(_status != _ENTERED, "ReentrancyGuard: reentrant call");
        _status = _ENTERED;
    }

    function _nonReentrantAfter() private {
       
        _status = _NOT_ENTERED;
    }
}


pragma solidity ^0.8.0;


library Math {
    enum Rounding {
        Down,
        Up, 
        Zero 
    }

    
    function max(uint256 a, uint256 b) internal pure returns (uint256) {
        return a > b ? a : b;
    }

    
    function min(uint256 a, uint256 b) internal pure returns (uint256) {
        return a < b ? a : b;
    }

    
    function average(uint256 a, uint256 b) internal pure returns (uint256) {
        // (a + b) / 2 can overflow.
        return (a & b) + (a ^ b) / 2;
    }

  
    function ceilDiv(uint256 a, uint256 b) internal pure returns (uint256) {
        // (a + b - 1) / b can overflow on addition, so we distribute.
        return a == 0 ? 0 : (a - 1) / b + 1;
    }

    
    function mulDiv(
        uint256 x,
        uint256 y,
        uint256 denominator
    ) internal pure returns (uint256 result) {
        unchecked {
            
            uint256 prod0; 
            uint256 prod1; 
            assembly {
                let mm := mulmod(x, y, not(0))
                prod0 := mul(x, y)
                prod1 := sub(sub(mm, prod0), lt(mm, prod0))
            }

            
            if (prod1 == 0) {
                return prod0 / denominator;
            }

            
            require(denominator > prod1);
            uint256 remainder;
            assembly {
                remainder := mulmod(x, y, denominator)

                prod1 := sub(prod1, gt(remainder, prod0))
                prod0 := sub(prod0, remainder)
            }
            uint256 twos = denominator & (~denominator + 1);
            assembly {
                denominator := div(denominator, twos)
                prod0 := div(prod0, twos)
                twos := add(div(sub(0, twos), twos), 1)
            }
            prod0 |= prod1 * twos;
            uint256 inverse = (3 * denominator) ^ 2;
            inverse *= 2 - denominator * inverse; 
            inverse *= 2 - denominator * inverse; 
            inverse *= 2 - denominator * inverse; 
            inverse *= 2 - denominator * inverse; 
            inverse *= 2 - denominator * inverse; 
            inverse *= 2 - denominator * inverse; 
            result = prod0 * inverse;
            return result;
        }
    }
    function mulDiv(
        uint256 x,
        uint256 y,
        uint256 denominator,
        Rounding rounding
    ) internal pure returns (uint256) {
        uint256 result = mulDiv(x, y, denominator);
        if (rounding == Rounding.Up && mulmod(x, y, denominator) > 0) {
            result += 1;
        }
        return result;
    }
    function sqrt(uint256 a) internal pure returns (uint256) {
        if (a == 0) {
            return 0;
        }
        uint256 result = 1 << (log2(a) >> 1);
        unchecked {
            result = (result + a / result) >> 1;
            result = (result + a / result) >> 1;
            result = (result + a / result) >> 1;
            result = (result + a / result) >> 1;
            result = (result + a / result) >> 1;
            result = (result + a / result) >> 1;
            result = (result + a / result) >> 1;
            return min(result, a / result);
        }
    }
    function sqrt(uint256 a, Rounding rounding) internal pure returns (uint256) {
        unchecked {
            uint256 result = sqrt(a);
            return result + (rounding == Rounding.Up && result * result < a ? 1 : 0);
        }
    }
    function log2(uint256 value) internal pure returns (uint256) {
        uint256 result = 0;
        unchecked {
            if (value >> 128 > 0) {
                value >>= 128;
                result += 128;
            }
            if (value >> 64 > 0) {
                value >>= 64;
                result += 64;
            }
            if (value >> 32 > 0) {
                value >>= 32;
                result += 32;
            }
            if (value >> 16 > 0) {
                value >>= 16;
                result += 16;
            }
            if (value >> 8 > 0) {
                value >>= 8;
                result += 8;
            }
            if (value >> 4 > 0) {
                value >>= 4;
                result += 4;
            }
            if (value >> 2 > 0) {
                value >>= 2;
                result += 2;
            }
            if (value >> 1 > 0) {
                result += 1;
            }
        }
        return result;
    }
    function log2(uint256 value, Rounding rounding) internal pure returns (uint256) {
        unchecked {
            uint256 result = log2(value);
            return result + (rounding == Rounding.Up && 1 << result < value ? 1 : 0);
        }
    }
    function log10(uint256 value) internal pure returns (uint256) {
        uint256 result = 0;
        unchecked {
            if (value >= 10**64) {
                value /= 10**64;
                result += 64;
            }
            if (value >= 10**32) {
                value /= 10**32;
                result += 32;
            }
            if (value >= 10**16) {
                value /= 10**16;
                result += 16;
            }
            if (value >= 10**8) {
                value /= 10**8;
                result += 8;
            }
            if (value >= 10**4) {
                value /= 10**4;
                result += 4;
            }
            if (value >= 10**2) {
                value /= 10**2;
                result += 2;
            }
            if (value >= 10**1) {
                result += 1;
            }
        }
        return result;
    }
    function log10(uint256 value, Rounding rounding) internal pure returns (uint256) {
        unchecked {
            uint256 result = log10(value);
            return result + (rounding == Rounding.Up && 10**result < value ? 1 : 0);
        }
    }
    function log256(uint256 value) internal pure returns (uint256) {
        uint256 result = 0;
        unchecked {
            if (value >> 128 > 0) {
                value >>= 128;
                result += 16;
            }
            if (value >> 64 > 0) {
                value >>= 64;
                result += 8;
            }
            if (value >> 32 > 0) {
                value >>= 32;
                result += 4;
            }
            if (value >> 16 > 0) {
                value >>= 16;
                result += 2;
            }
            if (value >> 8 > 0) {
                result += 1;
            }
        }
        return result;
    }
    function log256(uint256 value, Rounding rounding) internal pure returns (uint256) {
        unchecked {
            uint256 result = log256(value);
            return result + (rounding == Rounding.Up && 1 << (result * 8) < value ? 1 : 0);
        }
    }
}
pragma solidity ^0.8.0;
library Strings {
    bytes16 private constant _SYMBOLS = "0123456789abcdef";
    uint8 private constant _ADDRESS_LENGTH = 20;
    function toString(uint256 value) internal pure returns (string memory) {
        unchecked {
            uint256 length = Math.log10(value) + 1;
            string memory buffer = new string(length);
            uint256 ptr;
            
            assembly {
                ptr := add(buffer, add(32, length))
            }
            while (true) {
                ptr--;
                
                assembly {
                    mstore8(ptr, byte(mod(value, 10), _SYMBOLS))
                }
                value /= 10;
                if (value == 0) break;
            }
            return buffer;
        }
    }

    function toHexString(uint256 value) internal pure returns (string memory) {
        unchecked {
            return toHexString(value, Math.log256(value) + 1);
        }
    }

    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] = _SYMBOLS[value & 0xf];
            value >>= 4;
        }
        require(value == 0, "Strings: hex length insufficient");
        return string(buffer);
    }

    function toHexString(address addr) internal pure returns (string memory) {
        return toHexString(uint256(uint160(addr)), _ADDRESS_LENGTH);
    }
}
pragma solidity ^0.8.0;
abstract contract Context {
    function _msgSender() internal view virtual returns (address) {
        return msg.sender;
    }

    function _msgData() internal view virtual returns (bytes calldata) {
        return msg.data;
    }
}

pragma solidity ^0.8.0;

abstract contract Ownable is Context {
    address private _owner;

    event OwnershipTransferred(address indexed previousOwner, address indexed newOwner);

    constructor() {
        _transferOwnership(_msgSender());
    }
    modifier onlyOwner() {
        _checkOwner();
        _;
    }
    function owner() public view virtual returns (address) {
        return _owner;
    }
    function _checkOwner() internal view virtual {
        require(owner() == _msgSender(), "Ownable: caller is not the owner");
    }
    function renounceOwnership() public virtual onlyOwner {
        _transferOwnership(address(0));
    }
    function transferOwnership(address newOwner) public virtual onlyOwner {
        require(newOwner != address(0), "Ownable: new owner is the zero address");
        _transferOwnership(newOwner);
    }
    function _transferOwnership(address newOwner) internal virtual {
        address oldOwner = _owner;
        _owner = newOwner;
        emit OwnershipTransferred(oldOwner, newOwner);
    }
}

pragma solidity ^0.8.4;

interface IERC721A {
    error ApprovalCallerNotOwnerNorApproved();
    error ApprovalQueryForNonexistentToken();
    error BalanceQueryForZeroAddress();
    error MintToZeroAddress();
    error MintZeroQuantity();
    error OwnerQueryForNonexistentToken();
    error TransferCallerNotOwnerNorApproved();
    error TransferFromIncorrectOwner();
    error TransferToNonERC721ReceiverImplementer();
    error TransferToZeroAddress();
    error URIQueryForNonexistentToken();
    error MintERC2309QuantityExceedsLimit();
    error OwnershipNotInitializedForExtraData();

    struct TokenOwnership {
       
        address addr;
        uint64 startTimestamp;
        bool burned;
        uint24 extraData;
    }
    function totalSupply() external view returns (uint256);
    function supportsInterface(bytes4 interfaceId) external view returns (bool);
    event Transfer(address indexed from, address indexed to, uint256 indexed tokenId);
    event Approval(address indexed owner, address indexed approved, uint256 indexed tokenId);
    event ApprovalForAll(address indexed owner, address indexed operator, bool approved);
    function balanceOf(address owner) external view returns (uint256 balance);
    function ownerOf(uint256 tokenId) external view returns (address owner);
    function safeTransferFrom(
        address from,
        address to,
        uint256 tokenId,
        bytes calldata data
    ) external payable;
    function safeTransferFrom(
        address from,
        address to,
        uint256 tokenId
    ) external payable;
    function transferFrom(
        address from,
        address to,
        uint256 tokenId
    ) external payable;
    function approve(address to, uint256 tokenId) external payable;
    function setApprovalForAll(address operator, bool _approved) external;
    function getApproved(uint256 tokenId) external view returns (address operator);
    function isApprovedForAll(address owner, address operator) external view returns (bool);
    function name() external view returns (string memory);
    function symbol() external view returns (string memory);
    function tokenURI(uint256 tokenId) external view returns (string memory);
    event ConsecutiveTransfer(uint256 indexed fromTokenId, uint256 toTokenId, address indexed from, address indexed to);
}

pragma solidity ^0.8.4;
interface ERC721A__IERC721Receiver {
    function onERC721Received(
        address operator,
        address from,
        uint256 tokenId,
        bytes calldata data
    ) external returns (bytes4);
}
contract ERC721A is IERC721A {
    struct TokenApprovalRef {
        address value;
    }
    uint256 private constant _BITMASK_ADDRESS_DATA_ENTRY = (1 << 64) - 1;
    uint256 private constant _BITPOS_NUMBER_MINTED = 64;
    uint256 private constant _BITPOS_NUMBER_BURNED = 128;
    uint256 private constant _BITPOS_AUX = 192;
    uint256 private constant _BITMASK_AUX_COMPLEMENT = (1 << 192) - 1;
    uint256 private constant _BITPOS_START_TIMESTAMP = 160;
    uint256 private constant _BITMASK_BURNED = 1 << 224;
    uint256 private constant _BITPOS_NEXT_INITIALIZED = 225;
    uint256 private constant _BITMASK_NEXT_INITIALIZED = 1 << 225;
    uint256 private constant _BITPOS_EXTRA_DATA = 232;
    uint256 private constant _BITMASK_EXTRA_DATA_COMPLEMENT = (1 << 232) - 1;
    uint256 private constant _BITMASK_ADDRESS = (1 << 160) - 1;
    uint256 private constant _MAX_MINT_ERC2309_QUANTITY_LIMIT = 5000;
    bytes32 private constant _TRANSFER_EVENT_SIGNATURE =
        0xddf252ad1be2c89b69c2b068fc378daa952ba7f163c4a11628f55a4df523b3ef;
    uint256 private _currentIndex;
    uint256 private _burnCounter;
    string private _name;
    string private _symbol;
    mapping(uint256 => uint256) private _packedOwnerships;
    mapping(address => uint256) private _packedAddressData;
    mapping(uint256 => TokenApprovalRef) private _tokenApprovals;
    mapping(address => mapping(address => bool)) private _operatorApprovals;

    constructor(string memory name_, string memory symbol_) {
        _name = name_;
        _symbol = symbol_;
        _currentIndex = _startTokenId();
    }
    function _startTokenId() internal view virtual returns (uint256) {
        return 0;
    }
    function _nextTokenId() internal view virtual returns (uint256) {
        return _currentIndex;
    }
    function totalSupply() public view virtual override returns (uint256) {
        unchecked {
            return _currentIndex - _burnCounter - _startTokenId();
        }
    }
    function _totalMinted() internal view virtual returns (uint256) {
        unchecked {
            return _currentIndex - _startTokenId();
        }
    }
    function _totalBurned() internal view virtual returns (uint256) {
        return _burnCounter;
    }
    function balanceOf(address owner) public view virtual override returns (uint256) {
        if (owner == address(0)) revert BalanceQueryForZeroAddress();
        return _packedAddressData[owner] & _BITMASK_ADDRESS_DATA_ENTRY;
    }
    function _numberMinted(address owner) internal view returns (uint256) {
        return (_packedAddressData[owner] >> _BITPOS_NUMBER_MINTED) & _BITMASK_ADDRESS_DATA_ENTRY;
    }
    function _numberBurned(address owner) internal view returns (uint256) {
        return (_packedAddressData[owner] >> _BITPOS_NUMBER_BURNED) & _BITMASK_ADDRESS_DATA_ENTRY;
    }
    function _getAux(address owner) internal view returns (uint64) {
        return uint64(_packedAddressData[owner] >> _BITPOS_AUX);
    }
    function _setAux(address owner, uint64 aux) internal virtual {
        uint256 packed = _packedAddressData[owner];
        uint256 auxCasted;
        assembly {
            auxCasted := aux
        }
        packed = (packed & _BITMASK_AUX_COMPLEMENT) | (auxCasted << _BITPOS_AUX);
        _packedAddressData[owner] = packed;
    }
    function supportsInterface(bytes4 interfaceId) public view virtual override returns (bool) {

        return
            interfaceId == 0x01ffc9a7 || // ERC165 interface ID for ERC165.
            interfaceId == 0x80ac58cd || // ERC165 interface ID for ERC721.
            interfaceId == 0x5b5e139f; // ERC165 interface ID for ERC721Metadata.
    }
    function name() public view virtual override returns (string memory) {
        return _name;
    }
    function symbol() public view virtual override returns (string memory) {
        return _symbol;
    }
    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))) : '';
    }
    function _baseURI() internal view virtual returns (string memory) {
        return '';
    }
    function ownerOf(uint256 tokenId) public view virtual override returns (address) {
        return address(uint160(_packedOwnershipOf(tokenId)));
    }
    function _ownershipOf(uint256 tokenId) internal view virtual returns (TokenOwnership memory) {
        return _unpackedOwnership(_packedOwnershipOf(tokenId));
    }
    function _ownershipAt(uint256 index) internal view virtual returns (TokenOwnership memory) {
        return _unpackedOwnership(_packedOwnerships[index]);
    }
    function _initializeOwnershipAt(uint256 index) internal virtual {
        if (_packedOwnerships[index] == 0) {
            _packedOwnerships[index] = _packedOwnershipOf(index);
        }
    }
    function _packedOwnershipOf(uint256 tokenId) private view returns (uint256) {
        uint256 curr = tokenId;

        unchecked {
            if (_startTokenId() <= curr)
                if (curr < _currentIndex) {
                    uint256 packed = _packedOwnerships[curr];
                    if (packed & _BITMASK_BURNED == 0) {
                        while (packed == 0) {
                            packed = _packedOwnerships[--curr];
                        }
                        return packed;
                    }
                }
        }
        revert OwnerQueryForNonexistentToken();
    }
    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);
    }
    function _packOwnershipData(address owner, uint256 flags) private view returns (uint256 result) {
        assembly {
            owner := and(owner, _BITMASK_ADDRESS)
            result := or(owner, or(shl(_BITPOS_START_TIMESTAMP, timestamp()), flags))
        }
    }
    function _nextInitializedFlag(uint256 quantity) private pure returns (uint256 result) {
        assembly {
            result := shl(_BITPOS_NEXT_INITIALIZED, eq(quantity, 1))
        }
    }
    function approve(address to, uint256 tokenId) public payable virtual override {
        address owner = ownerOf(tokenId);

        if (_msgSenderERC721A() != owner)
            if (!isApprovedForAll(owner, _msgSenderERC721A())) {
                revert ApprovalCallerNotOwnerNorApproved();
            }

        _tokenApprovals[tokenId].value = to;
        emit Approval(owner, to, tokenId);
    }
    function getApproved(uint256 tokenId) public view virtual override returns (address) {
        if (!_exists(tokenId)) revert ApprovalQueryForNonexistentToken();

        return _tokenApprovals[tokenId].value;
    }
    function setApprovalForAll(address operator, bool approved) public virtual override {
        _operatorApprovals[_msgSenderERC721A()][operator] = approved;
        emit ApprovalForAll(_msgSenderERC721A(), operator, approved);
    }
    function isApprovedForAll(address owner, address operator) public view virtual override returns (bool) {
        return _operatorApprovals[owner][operator];
    }
    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.
    }
    function _isSenderApprovedOrOwner(
        address approvedAddress,
        address owner,
        address msgSender
    ) private pure returns (bool result) {
        assembly {
            owner := and(owner, _BITMASK_ADDRESS)
            msgSender := and(msgSender, _BITMASK_ADDRESS)
            result := or(eq(msgSender, owner), eq(msgSender, approvedAddress))
        }
    }
    function _getApprovedSlotAndAddress(uint256 tokenId)
        private
        view
        returns (uint256 approvedAddressSlot, address approvedAddress)
    {
        TokenApprovalRef storage tokenApproval = _tokenApprovals[tokenId];
        assembly {
            approvedAddressSlot := tokenApproval.slot
            approvedAddress := sload(approvedAddressSlot)
        }
    }
    function transferFrom(
        address from,
        address to,
        uint256 tokenId
    ) public payable virtual override {
        uint256 prevOwnershipPacked = _packedOwnershipOf(tokenId);

        if (address(uint160(prevOwnershipPacked)) != from) revert TransferFromIncorrectOwner();

        (uint256 approvedAddressSlot, address approvedAddress) = _getApprovedSlotAndAddress(tokenId);
        if (!_isSenderApprovedOrOwner(approvedAddress, from, _msgSenderERC721A()))
            if (!isApprovedForAll(from, _msgSenderERC721A())) revert TransferCallerNotOwnerNorApproved();

        if (to == address(0)) revert TransferToZeroAddress();

        _beforeTokenTransfers(from, to, tokenId, 1);
        assembly {
            if approvedAddress {
                sstore(approvedAddressSlot, 0)
            }
        }
        unchecked {
            --_packedAddressData[from]; // Updates: `balance -= 1`.
            ++_packedAddressData[to]; // Updates: `balance += 1`.
            _packedOwnerships[tokenId] = _packOwnershipData(
                to,
                _BITMASK_NEXT_INITIALIZED | _nextExtraData(from, to, prevOwnershipPacked)
            );
            if (prevOwnershipPacked & _BITMASK_NEXT_INITIALIZED == 0) {
                uint256 nextTokenId = tokenId + 1;
                if (_packedOwnerships[nextTokenId] == 0) {
                    if (nextTokenId != _currentIndex) {
                        _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 payable virtual override {
        safeTransferFrom(from, to, tokenId, '');
    }
    function safeTransferFrom(
        address from,
        address to,
        uint256 tokenId,
        bytes memory _data
    ) public payable virtual override {
        transferFrom(from, to, tokenId);
        if (to.code.length != 0)
            if (!_checkContractOnERC721Received(from, to, tokenId, _data)) {
                revert TransferToNonERC721ReceiverImplementer();
            }
    }
    function _beforeTokenTransfers(
        address from,
        address to,
        uint256 startTokenId,
        uint256 quantity
    ) internal virtual {}
    function _afterTokenTransfers(
        address from,
        address to,
        uint256 startTokenId,
        uint256 quantity
    ) internal virtual {}
    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))
                }
            }
        }
    }
    function _mint(address to, uint256 quantity) internal virtual {
        uint256 startTokenId = _currentIndex;
        if (quantity == 0) revert MintZeroQuantity();

        _beforeTokenTransfers(address(0), to, startTokenId, quantity);
        unchecked {
            _packedAddressData[to] += quantity * ((1 << _BITPOS_NUMBER_MINTED) | 1);
            _packedOwnerships[startTokenId] = _packOwnershipData(
                to,
                _nextInitializedFlag(quantity) | _nextExtraData(address(0), to, 0)
            );

            uint256 toMasked;
            uint256 end = startTokenId + quantity;
            assembly {
                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)
                }
                 {
                    log4(0, 0, _TRANSFER_EVENT_SIGNATURE, 0, toMasked, tokenId)
                }
            }
            if (toMasked == 0) revert MintToZeroAddress();

            _currentIndex = end;
        }
        _afterTokenTransfers(address(0), to, startTokenId, quantity);
    }
    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);

        unchecked {
            _packedAddressData[to] += quantity * ((1 << _BITPOS_NUMBER_MINTED) | 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);
    }
    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();
            }
        }
    }
    function _safeMint(address to, uint256 quantity) internal virtual {
        _safeMint(to, quantity, '');
    }
    function _burn(uint256 tokenId) internal virtual {
        _burn(tokenId, false);
    }
    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) {
            if (!_isSenderApprovedOrOwner(approvedAddress, from, _msgSenderERC721A()))
                if (!isApprovedForAll(from, _msgSenderERC721A())) revert TransferCallerNotOwnerNorApproved();
        }

        _beforeTokenTransfers(from, address(0), tokenId, 1);
        assembly {
            if approvedAddress {
                sstore(approvedAddressSlot, 0)
            }
        }
        unchecked {
            _packedAddressData[from] += (1 << _BITPOS_NUMBER_BURNED) - 1;
            _packedOwnerships[tokenId] = _packOwnershipData(
                from,
                (_BITMASK_BURNED | _BITMASK_NEXT_INITIALIZED) | _nextExtraData(from, address(0), prevOwnershipPacked)
            );
            if (prevOwnershipPacked & _BITMASK_NEXT_INITIALIZED == 0) {
                uint256 nextTokenId = tokenId + 1;
                if (_packedOwnerships[nextTokenId] == 0) {
                    if (nextTokenId != _currentIndex) {
                        _packedOwnerships[nextTokenId] = prevOwnershipPacked;
                    }
                }
            }
        }

        emit Transfer(from, address(0), tokenId);
        _afterTokenTransfers(from, address(0), tokenId, 1);
        unchecked {
            _burnCounter++;
        }
    }
    function _setExtraDataAt(uint256 index, uint24 extraData) internal virtual {
        uint256 packed = _packedOwnerships[index];
        if (packed == 0) revert OwnershipNotInitializedForExtraData();
        uint256 extraDataCasted;
        assembly {
            extraDataCasted := extraData
        }
        packed = (packed & _BITMASK_EXTRA_DATA_COMPLEMENT) | (extraDataCasted << _BITPOS_EXTRA_DATA);
        _packedOwnerships[index] = packed;
    }
    function _extraData(
        address from,
        address to,
        uint24 previousExtraData
    ) internal view virtual returns (uint24) {}
    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;
    }
    function _msgSenderERC721A() internal view virtual returns (address) {
        return msg.sender;
    }
    function _toString(uint256 value) internal pure virtual returns (string memory str) {
        assembly {
            let m := add(mload(0x40), 0xa0)
            mstore(0x40, m)
            str := sub(m, 0x20)
            mstore(str, 0)
            let end := str
            for { let temp := value } 1 {} {
                str := sub(str, 1)
                mstore8(str, add(48, mod(temp, 10)))
                temp := div(temp, 10)
                if iszero(temp) { break }
            }

            let length := sub(end, str)
            str := sub(str, 0x20)
            mstore(str, length)
        }
    }
}

pragma solidity >=0.7.0 <0.9.0;

contract BitcoinBoyz is ERC721A, Ownable, ReentrancyGuard {
  using Strings for uint256;

  string public baseURI;
  string public baseExtension = ".json";
  string public notRevealedUri;
  uint256 public cost = 0.002 ether;
  uint256 public maxSupply = 6969;
  uint256 public FreeSupply = 1500;
  uint256 public MaxperWallet = 20;
  uint256 public MaxperWalletFree = 10;
  bool public paused = false;
  bool public revealed = false;

  constructor(
    string memory _initBaseURI,
    string memory _notRevealedUri
  ) ERC721A("BitcoinBoyz", "BTCBOYZ") {  // change the name and symbol for your collection
    setBaseURI(_initBaseURI);
    setNotRevealedURI(_notRevealedUri);
  }
  function _baseURI() internal view virtual override returns (string memory) {
    return baseURI;
  }
      function _startTokenId() internal view virtual override returns (uint256) {
        return 1;
    }
  function mint(uint256 tokens) public payable nonReentrant {
    require(!paused, "oops contract is paused");
    require(tokens <= MaxperWallet, "max mint amount per tx exceeded");
    require(totalSupply() + tokens <= maxSupply, "We Soldout");
    require(_numberMinted(_msgSenderERC721A()) + tokens <= MaxperWallet, "Max NFT Per Wallet exceeded");
    require(msg.value >= cost * tokens, "insufficient funds");

      _safeMint(_msgSenderERC721A(), tokens);
  }
    function freemint(uint256 tokens) public nonReentrant {
    require(!paused, "oops contract is paused");
    require(_numberMinted(_msgSenderERC721A()) + tokens <= MaxperWalletFree, "Max NFT Per Wallet exceeded");
    require(tokens <= MaxperWalletFree, "max mint per Tx exceeded");
    require(totalSupply() + tokens <= FreeSupply, "Whitelist MaxSupply exceeded");

      _safeMint(_msgSenderERC721A(), tokens);
    
  }
     function airdrop(uint256 _mintAmount, address destination) public onlyOwner nonReentrant {
    require(totalSupply() + _mintAmount <= maxSupply, "max NFT limit exceeded");

      _safeMint(destination, _mintAmount);
  }
  function tokenURI(uint256 tokenId)
    public
    view
    virtual
    override
    returns (string memory)
  {
    require(
      _exists(tokenId),
      "ERC721AMetadata: URI query for nonexistent token"
    );
    
    if(revealed == false) {
        return notRevealedUri;
    }

    string memory currentBaseURI = _baseURI();
    return bytes(currentBaseURI).length > 0
        ? string(abi.encodePacked(currentBaseURI, tokenId.toString(), baseExtension))
        : "";
  }
    function numberMinted(address owner) public view returns (uint256) {
    return _numberMinted(owner);
  }
      function tokensOfOwner(address owner) public view returns (uint256[] memory) {
        unchecked {
            uint256 tokenIdsIdx;
            address currOwnershipAddr;
            uint256 tokenIdsLength = balanceOf(owner);
            uint256[] memory tokenIds = new uint256[](tokenIdsLength);
            TokenOwnership memory ownership;
            for (uint256 i = _startTokenId(); tokenIdsIdx != tokenIdsLength; ++i) {
                ownership = _ownershipAt(i);
                if (ownership.burned) {
                    continue;
                }
                if (ownership.addr != address(0)) {
                    currOwnershipAddr = ownership.addr;
                }
                if (currOwnershipAddr == owner) {
                    tokenIds[tokenIdsIdx++] = i;
                }
            }
            return tokenIds;
        }
    }
  function reveal(bool _state) public onlyOwner {
      revealed = _state;
  }
  function setMaxPerWallet(uint256 _limit) public onlyOwner {
    MaxperWallet = _limit;
  }
    function setFreeMaxPerWallet(uint256 _limit) public onlyOwner {
    MaxperWalletFree = _limit;
  }
  function setCost(uint256 _newCost) public onlyOwner {
    cost = _newCost;
  }
    function setMaxsupply(uint256 _newsupply) public onlyOwner {
    maxSupply = _newsupply;
  }
    function setFreesupply(uint256 _newsupply) public onlyOwner {
    FreeSupply = _newsupply;
  }
  function setBaseURI(string memory _newBaseURI) public onlyOwner {
    baseURI = _newBaseURI;
  }
  function setBaseExtension(string memory _newBaseExtension) public onlyOwner {
    baseExtension = _newBaseExtension;
  }
  function setNotRevealedURI(string memory _notRevealedURI) public onlyOwner {
    notRevealedUri = _notRevealedURI;
  }
  function pause(bool _state) public onlyOwner {
    paused = _state;
  }
  function withdraw() public payable onlyOwner nonReentrant {
      uint256 balance = address(this).balance;
      payable(_msgSenderERC721A()).transfer(balance);
  }
}