// SPDX-License-Identifier: MIT                                          
// 
// 


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 ^0.8.0;

abstract contract ReentrancyGuard {

    uint256 private constant _NOT_ENTERED = 1;
    uint256 private constant _ENTERED = 2;

    uint256 private _status;

    constructor() {
        _status = _NOT_ENTERED;
    }

    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;

        _;

        _status = _NOT_ENTERED;
    }
}

pragma solidity ^0.8.0;

library Strings {
    bytes16 private constant _HEX_SYMBOLS = "0123456789abcdef";
    uint8 private constant _ADDRESS_LENGTH = 20;

    function toString(uint256 value) internal pure returns (string memory) {

        if (value == 0) {
            return "0";
        }
        uint256 temp = value;
        uint256 digits;
        while (temp != 0) {
            digits++;
            temp /= 10;
        }
        bytes memory buffer = new bytes(digits);
        while (value != 0) {
            digits -= 1;
            buffer[digits] = bytes1(uint8(48 + uint256(value % 10)));
            value /= 10;
        }
        return string(buffer);
    }

    function toHexString(uint256 value) internal pure returns (string memory) {
        if (value == 0) {
            return "0x00";
        }
        uint256 temp = value;
        uint256 length = 0;
        while (temp != 0) {
            length++;
            temp >>= 8;
        }
        return toHexString(value, length);
    }

    function toHexString(uint256 value, uint256 length) internal pure returns (string memory) {
        bytes memory buffer = new bytes(2 * length + 2);
        buffer[0] = "0";
        buffer[1] = "x";
        for (uint256 i = 2 * length + 1; i > 1; --i) {
            buffer[i] = _HEX_SYMBOLS[value & 0xf];
            value >>= 4;
        }
        require(value == 0, "Strings: hex length insufficient");
        return string(buffer);
    }

    function toHexString(address addr) internal pure returns (string memory) {
        return toHexString(uint256(uint160(addr)), _ADDRESS_LENGTH);
    }
}

pragma solidity ^0.8.0;


library EnumerableSet {


    struct Set {
        // Storage of set values
        bytes32[] _values;

        mapping(bytes32 => uint256) _indexes;
    }

    function _add(Set storage set, bytes32 value) private returns (bool) {
        if (!_contains(set, value)) {
            set._values.push(value);

            set._indexes[value] = set._values.length;
            return true;
        } else {
            return false;
        }
    }

    function _remove(Set storage set, bytes32 value) private returns (bool) {

        uint256 valueIndex = set._indexes[value];

        if (valueIndex != 0) {

            uint256 toDeleteIndex = valueIndex - 1;
            uint256 lastIndex = set._values.length - 1;

            if (lastIndex != toDeleteIndex) {
                bytes32 lastValue = set._values[lastIndex];

                set._values[toDeleteIndex] = lastValue;
                
                set._indexes[lastValue] = valueIndex; 
            }

            // Delete the slot where the moved value was stored
            set._values.pop();

            // Delete the index for the deleted slot
            delete set._indexes[value];

            return true;
        } else {
            return false;
        }
    }

    function _contains(Set storage set, bytes32 value) private view returns (bool) {
        return set._indexes[value] != 0;
    }

    function _length(Set storage set) private view returns (uint256) {
        return set._values.length;
    }

    function _at(Set storage set, uint256 index) private view returns (bytes32) {
        return set._values[index];
    }

    function _values(Set storage set) private view returns (bytes32[] memory) {
        return set._values;
    }

    struct Bytes32Set {
        Set _inner;
    }

    function add(Bytes32Set storage set, bytes32 value) internal returns (bool) {
        return _add(set._inner, value);
    }

    function remove(Bytes32Set storage set, bytes32 value) internal returns (bool) {
        return _remove(set._inner, value);
    }

    function contains(Bytes32Set storage set, bytes32 value) internal view returns (bool) {
        return _contains(set._inner, value);
    }

    function length(Bytes32Set storage set) internal view returns (uint256) {
        return _length(set._inner);
    }

    function at(Bytes32Set storage set, uint256 index) internal view returns (bytes32) {
        return _at(set._inner, index);
    }

    function values(Bytes32Set storage set) internal view returns (bytes32[] memory) {
        return _values(set._inner);
    }

    struct AddressSet {
        Set _inner;
    }

    function add(AddressSet storage set, address value) internal returns (bool) {
        return _add(set._inner, bytes32(uint256(uint160(value))));
    }

    function remove(AddressSet storage set, address value) internal returns (bool) {
        return _remove(set._inner, bytes32(uint256(uint160(value))));
    }

    function contains(AddressSet storage set, address value) internal view returns (bool) {
        return _contains(set._inner, bytes32(uint256(uint160(value))));
    }

    function length(AddressSet storage set) internal view returns (uint256) {
        return _length(set._inner);
    }

    function at(AddressSet storage set, uint256 index) internal view returns (address) {
        return address(uint160(uint256(_at(set._inner, index))));
    }

    function values(AddressSet storage set) internal view returns (address[] memory) {
        bytes32[] memory store = _values(set._inner);
        address[] memory result;

        assembly {
            result := store
        }

        return result;
    }

    struct UintSet {
        Set _inner;
    }

    function add(UintSet storage set, uint256 value) internal returns (bool) {
        return _add(set._inner, bytes32(value));
    }

    function remove(UintSet storage set, uint256 value) internal returns (bool) {
        return _remove(set._inner, bytes32(value));
    }

    function contains(UintSet storage set, uint256 value) internal view returns (bool) {
        return _contains(set._inner, bytes32(value));
    }

    function length(UintSet storage set) internal view returns (uint256) {
        return _length(set._inner);
    }

    function at(UintSet storage set, uint256 index) internal view returns (uint256) {
        return uint256(_at(set._inner, index));
    }

    function values(UintSet storage set) internal view returns (uint256[] memory) {
        bytes32[] memory store = _values(set._inner);
        uint256[] memory result;

        /// @solidity memory-safe-assembly
        assembly {
            result := store
        }

        return result;
    }
}

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;
        // Cast `aux` with assembly to avoid redundant masking.
        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 || 
            interfaceId == 0x80ac58cd || 
            interfaceId == 0x5b5e139f; 
    }

    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 {
            // 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))
        }
    }

    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))
        }
    }

    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]; 
            ++_packedAddressData[to]; 

            _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);
    }

    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)

                log4(
                    0, 
                    0, 
                    _TRANSFER_EVENT_SIGNATURE, 
                    0, 
                    toMasked, 
                    startTokenId 
                )

                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 ^0.8.13;

contract OperatorFilterer {
    error OperatorNotAllowed(address operator);

    IOperatorFilterRegistry constant operatorFilterRegistry =
        IOperatorFilterRegistry(0x000000000000AAeB6D7670E522A718067333cd4E);

    constructor(address subscriptionOrRegistrantToCopy, bool subscribe) {

        if (address(operatorFilterRegistry).code.length > 0) {
            if (subscribe) {
                operatorFilterRegistry.registerAndSubscribe(address(this), subscriptionOrRegistrantToCopy);
            } else {
                if (subscriptionOrRegistrantToCopy != address(0)) {
                    operatorFilterRegistry.registerAndCopyEntries(address(this), subscriptionOrRegistrantToCopy);
                } else {
                    operatorFilterRegistry.register(address(this));
                }
            }
        }
    }

    modifier onlyAllowedOperator() virtual {

        if (address(operatorFilterRegistry).code.length > 0) {
            if (!operatorFilterRegistry.isOperatorAllowed(address(this), msg.sender)) {
                revert OperatorNotAllowed(msg.sender);
            }
        }
        _;
    }
}

pragma solidity ^0.8.13;

contract DefaultOperatorFilterer is OperatorFilterer {
    address constant DEFAULT_SUBSCRIPTION = address(0x3cc6CddA760b79bAfa08dF41ECFA224f810dCeB6);

    constructor() OperatorFilterer(DEFAULT_SUBSCRIPTION, true) {}
}

pragma solidity ^0.8.13;

interface IOperatorFilterRegistry {
    function isOperatorAllowed(address registrant, address operator) external returns (bool);
    function register(address registrant) external;
    function registerAndSubscribe(address registrant, address subscription) external;
    function registerAndCopyEntries(address registrant, address registrantToCopy) external;
    function updateOperator(address registrant, address operator, bool filtered) external;
    function updateOperators(address registrant, address[] calldata operators, bool filtered) external;
    function updateCodeHash(address registrant, bytes32 codehash, bool filtered) external;
    function updateCodeHashes(address registrant, bytes32[] calldata codeHashes, bool filtered) external;
    function subscribe(address registrant, address registrantToSubscribe) external;
    function unsubscribe(address registrant, bool copyExistingEntries) external;
    function subscriptionOf(address addr) external returns (address registrant);
    function subscribers(address registrant) external returns (address[] memory);
    function subscriberAt(address registrant, uint256 index) external returns (address);
    function copyEntriesOf(address registrant, address registrantToCopy) external;
    function isOperatorFiltered(address registrant, address operator) external returns (bool);
    function isCodeHashOfFiltered(address registrant, address operatorWithCode) external returns (bool);
    function isCodeHashFiltered(address registrant, bytes32 codeHash) external returns (bool);
    function filteredOperators(address addr) external returns (address[] memory);
    function filteredCodeHashes(address addr) external returns (bytes32[] memory);
    function filteredOperatorAt(address registrant, uint256 index) external returns (address);
    function filteredCodeHashAt(address registrant, uint256 index) external returns (bytes32);
    function isRegistered(address addr) external returns (bool);
    function codeHashOf(address addr) external returns (bytes32);
}

pragma solidity ^0.8.4;

interface IERC721ABurnable is IERC721A {

    function burn(uint256 tokenId) external;
}

pragma solidity ^0.8.4;
abstract contract ERC721ABurnable is ERC721A, IERC721ABurnable {
    function burn(uint256 tokenId) public virtual override {
        _burn(tokenId, true);
    }
}

pragma solidity ^0.8.16;
contract PakInternship is Ownable, ERC721A, ReentrancyGuard, ERC721ABurnable, DefaultOperatorFilterer{
string public CONTRACT_URI = "";
mapping(address => uint) public userHasMinted;
bool public REVEALED;
string public UNREVEALED_URI = "";
string public BASE_URI = "ipfs://__CID__/hidden.json";
bool public isPublicMintEnabled = false;
uint public COLLECTION_SIZE = 111;
uint public MINT_PRICE = 0.0025 ether;
uint public MAX_BATCH_SIZE = 250;
uint public SUPPLY_PER_WALLET = 250;
uint public FREE_SUPPLY_PER_WALLET = 3;
constructor() ERC721A("Pak Internship", "PAKWEB3") {}


    function MintWL(uint256 quantity, address receiver) public onlyOwner {
        require(
            totalSupply() + quantity <= COLLECTION_SIZE,
            "No more Amigos in stock!"
        );
        
        _safeMint(receiver, quantity);
    }

    modifier callerIsUser() {
        require(tx.origin == msg.sender, "The caller is another contract");
        _;
    }

    function getPrice(uint quantity) public view returns(uint){
        uint price;
        uint free = FREE_SUPPLY_PER_WALLET - userHasMinted[msg.sender];
        if (quantity >= free) {
            price = (MINT_PRICE) * (quantity - free);
        } else {
            price = 0;
        }
        return price;
    }

    function mint(uint quantity)
        external
        payable
        callerIsUser 
        nonReentrant
    {
        uint price;
        uint free = FREE_SUPPLY_PER_WALLET - userHasMinted[msg.sender];
        if (quantity >= free) {
            price = (MINT_PRICE) * (quantity - free);
            userHasMinted[msg.sender] = userHasMinted[msg.sender] + free;
        } else {
            price = 0;
            userHasMinted[msg.sender] = userHasMinted[msg.sender] + quantity;
        }

        require(isPublicMintEnabled, "Amigos not ready yet!");
        require(totalSupply() + quantity <= COLLECTION_SIZE, "No more Amigos!");

        require(balanceOf(msg.sender) + quantity <= SUPPLY_PER_WALLET, "Tried to total mint Amigos per wallet over limit");

        require(quantity <= MAX_BATCH_SIZE, "Tried to mint Amigos over limit, retry with reduced quantity");
        require(msg.value >= price, "Must send enough eth");

        _safeMint(msg.sender, quantity);

        if (msg.value > price) {
            payable(msg.sender).transfer(msg.value - price);
        }
    }

    function withdrawFunds() external onlyOwner nonReentrant {
        (bool success, ) = msg.sender.call{value: address(this).balance}("");
        require(success, "Transfer failed.");
    }

    function setPublicMintEnabled() public onlyOwner {
        isPublicMintEnabled = !isPublicMintEnabled;
    }

    function setBaseURI(bool _revealed, string memory _baseURI) public onlyOwner {
        BASE_URI = _baseURI;
        REVEALED = _revealed;
    }

    function contractURI() public view returns (string memory) {
        return CONTRACT_URI;
    }

    function setContractURI(string memory _contractURI) public onlyOwner {
        CONTRACT_URI = _contractURI;
    }

    function setCOLLECTIONsIZE(uint256 _new) external onlyOwner {
        COLLECTION_SIZE = _new;
    }

    function setPrice(uint256 _newPrice) external onlyOwner {
        MINT_PRICE = _newPrice;
    }

    function set_FREE_SUPPLY_PER_WALLET(uint256 _new) external onlyOwner {
        FREE_SUPPLY_PER_WALLET = _new;
    }

    function set_SUPPLY_PER_WALLET(uint256 _new) external onlyOwner {
        SUPPLY_PER_WALLET = _new;
    }

    function set_MAX_BATCH_SIZE(uint256 _new) external onlyOwner {
        MAX_BATCH_SIZE = _new;
    }

    function transferFrom(address from, address to, uint256 tokenId) public payable override (ERC721A, IERC721A) onlyAllowedOperator {
        super.transferFrom(from, to, tokenId);
    }

    function safeTransferFrom(address from, address to, uint256 tokenId) public payable override (ERC721A, IERC721A) onlyAllowedOperator {
        super.safeTransferFrom(from, to, tokenId);
    }

    function safeTransferFrom(address from, address to, uint256 tokenId, bytes memory data)
        public payable
        override (ERC721A, IERC721A)
        onlyAllowedOperator
    {
        super.safeTransferFrom(from, to, tokenId, data);
    }

    function tokenURI(uint256 _tokenId)
        public
        view
        override (ERC721A, IERC721A)
        returns (string memory)
    {
        if (REVEALED) {
            return
                string(abi.encodePacked(BASE_URI, Strings.toString(_tokenId)));
        } else {
            return UNREVEALED_URI;
        }
    }

}