// File: contracts/Funga.sol



// SPDX-License-Identifier: MIT
pragma solidity 0.8.15;

import "@openzeppelin/contracts/utils/Address.sol";
import "@openzeppelin/contracts/utils/Context.sol";
import "@openzeppelin/contracts/utils/Strings.sol";
import "@openzeppelin/contracts/token/ERC20/IERC20.sol";
import "@openzeppelin/contracts/token/ERC721/IERC721.sol";
import "@openzeppelin/contracts/access/Ownable.sol";
import "@openzeppelin/contracts/security/ReentrancyGuard.sol";
import "@openzeppelin/contracts/utils/cryptography/MerkleProof.sol";
import "./ERC721AQueryable.sol";

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contract Funga is ERC721AQueryable, Ownable, ReentrancyGuard {
	using Address for address;
	using Strings for uint256;
	using MerkleProof for bytes32[];

	bytes32 public root = 0x7c692400d56fcdbe35a9ab6933326ccdf822412b680833be042823276f31ed97;
	bytes32 public root2 = 0x36f1900eacdb519374318bda0cec0eaeeda00af629e66d8dd58c5965e0bc0996;

	string public _contractBaseURI = "https://funga-backend.funga.io/contract_uri";
	string public _contractURI = "https://funga-backend.funga.io/metadata/";

	uint256 public maxSupply = 3333;
	uint256 public preSaleSupply = 1500;

	uint256 public presale1StartTime = block.timestamp - 1; // TODO: set it
	uint256 public presale2StartTime = presale1StartTime + 30 minutes; // TODO: set it
	uint256 public publicStartTime = block.timestamp - 1; // TODO: set it

	mapping(address => uint256) public usedAddresses; //merkle root check

	//owner: 0x473Facf7c8A5e1330d660f0DeFa3CAc2ED528407
	modifier notContract() {
		require(!_isContract(msg.sender), "not allowed");
		require(msg.sender == tx.origin, "proxy not allowed");
		_;
	}

	constructor() ERC721A("Funga", "FUNGA") {}

	/**
	 @dev only whitelisted can get one
	 @param proof - merkle proof
	  */
	function presale1Get(bytes32[] calldata proof) external nonReentrant notContract {
		require(usedAddresses[msg.sender] + 1 <= 1, "wallet limit reached");
		require(block.timestamp >= presale1StartTime, "not live");
		require(totalSupply() + 1 <= preSaleSupply, "out of stock");
		require(isProofValid(msg.sender, 1, proof), "invalid proof");

		usedAddresses[msg.sender] += 1;
		_mint(msg.sender, 1);
	}

	/**
	 @dev only whitelisted (part 2) can get one
	 @param proof - merkle proof
	  */
	function presale2Get(bytes32[] calldata proof) external nonReentrant notContract {
		require(usedAddresses[msg.sender] + 1 <= 1, "wallet limit reached");
		require(block.timestamp >= presale2StartTime, "not live");
		require(totalSupply() + 1 <= maxSupply, "out of stock");
		require(isProofValid2(msg.sender, 1, proof), "invalid proof");

		usedAddresses[msg.sender] += 1;
		_mint(msg.sender, 1);
	}

	/**
	 @dev everyone can get one even if you're not whitelisted
	  */
	function publicGet() external nonReentrant notContract {
		require(block.timestamp >= publicStartTime, "not live");
		require(totalSupply() + 1 <= maxSupply, "out of stock");
		require(usedAddresses[msg.sender] + 1 <= 1, "wallet limit reached");

		usedAddresses[msg.sender] += 1;
		_mint(msg.sender, 1);
	}

	/**
	 @dev admin mint
	 @param to - destination
	 @param qty - quantity
	  */
	function adminMint(address to, uint16 qty) external onlyOwner {
		require(qty < 21, "max 20 at once");
		_mint(to, qty);
	}

	/**
	 * READ FUNCTIONS
	 */
	function exists(uint256 _tokenId) external view returns (bool) {
		return _exists(_tokenId);
	}

	// function tokenURI(uint256 _tokenId) public view override returns (string memory) {
	// 	require(_exists(_tokenId), "ERC721Metadata: URI query for nonexistent token");

	// }

	function tokenURI(uint256 _tokenId)
		public
		view
		override(ERC721A, IERC721A)
		returns (string memory)
	{
		require(_exists(_tokenId), "ERC721Metadata: URI query for nonexistent token");
		return string(abi.encodePacked(_contractBaseURI, _tokenId.toString(), ".json"));
	}

	function contractURI() public view returns (string memory) {
		return _contractURI;
	}

	//merkle root check
	function isProofValid(
		address to,
		uint256 limit,
		bytes32[] memory proof
	) public view returns (bool) {
		bytes32 leaf = keccak256(abi.encodePacked(to, limit));
		return proof.verify(root, leaf);
	}

	//merkle root check
	function isProofValid2(
		address to,
		uint256 limit,
		bytes32[] memory proof
	) public view returns (bool) {
		bytes32 leaf = keccak256(abi.encodePacked(to, limit));
		return proof.verify(root2, leaf);
	}

	/**
	 * ADMIN FUNCTIONS
	 */
	function setImportantURIs(
		string memory newBaseURI,
		string memory newContractURI,
		string memory newUnrevealed
	) external onlyOwner {
		_contractBaseURI = newBaseURI;
		_contractURI = newContractURI;
	}

	//recover lost erc20. getting them back chance: very low
	function reclaimERC20Token(address erc20Token) external onlyOwner {
		IERC20(erc20Token).transfer(msg.sender, IERC20(erc20Token).balanceOf(address(this)));
	}

	//recover lost nfts. getting them back chance: very low
	function reclaimERC721(address erc721Token, uint256 id) external onlyOwner {
		IERC721(erc721Token).safeTransferFrom(address(this), msg.sender, id);
	}

	//contract doesn't accept eth, so this is not used
	function withdrawETH() public onlyOwner {
		payable(msg.sender).transfer(address(this).balance);
	}

	//change the presale start time
	function setStartTimes(
		uint256 presale1,
		uint256 presale2,
		uint256 publicSale
	) external onlyOwner {
		presale1StartTime = presale1;
		presale2StartTime = presale2;
		publicStartTime = publicSale;
	}

	//999 = sold out, 0 = not started, 1 = whitelist 1, 2 = whitelist 2, 3 = public
	function getStage() public view returns (uint256) {
		if (totalSupply() >= maxSupply) {
			return 999;
		}
		if (block.timestamp >= publicStartTime) {
			return 3;
		}
		if (block.timestamp >= presale2StartTime) {
			return 2;
		}
		if (block.timestamp >= presale1StartTime) {
			return 1;
		}
		return 0;
	}

	//only decrease it, no funky stuff
	function decreaseMaxSupply(uint256 newMaxSupply) external onlyOwner {
		require(newMaxSupply < maxSupply, "decrease only");
		maxSupply = newMaxSupply;
	}

	//call this to reveal the jpegs
	function setBaseURI(string memory newBaseURI) external onlyOwner {
		_contractBaseURI = newBaseURI;
	}

	function setMerkleRoot(bytes32 _root, bytes32 _root2) external onlyOwner {
		root = _root;
		root2 = _root2;
	}

	//anti-bot
	function _isContract(address _addr) private view returns (bool) {
		uint256 size;
		assembly {
			size := extcodesize(_addr)
		}
		return size > 0;
	}

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

	function buildNumber3() internal view {}
}

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



// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.7.0) (utils/Address.sol)

pragma solidity ^0.8.1;

/**
 * @dev Collection of functions related to the address type
 */
library Address {
    /**
     * @dev Returns true if `account` is a contract.
     *
     * [IMPORTANT]
     * ====
     * It is unsafe to assume that an address for which this function returns
     * false is an externally-owned account (EOA) and not a contract.
     *
     * Among others, `isContract` will return false for the following
     * types of addresses:
     *
     *  - an externally-owned account
     *  - a contract in construction
     *  - an address where a contract will be created
     *  - an address where a contract lived, but was destroyed
     * ====
     *
     * [IMPORTANT]
     * ====
     * You shouldn't rely on `isContract` to protect against flash loan attacks!
     *
     * Preventing calls from contracts is highly discouraged. It breaks composability, breaks support for smart wallets
     * like Gnosis Safe, and does not provide security since it can be circumvented by calling from a contract
     * constructor.
     * ====
     */
    function isContract(address account) internal view returns (bool) {
        // This method relies on extcodesize/address.code.length, which returns 0
        // for contracts in construction, since the code is only stored at the end
        // of the constructor execution.

        return account.code.length > 0;
    }

    /**
     * @dev Replacement for Solidity's `transfer`: sends `amount` wei to
     * `recipient`, forwarding all available gas and reverting on errors.
     *
     * https://eips.ethereum.org/EIPS/eip-1884[EIP1884] increases the gas cost
     * of certain opcodes, possibly making contracts go over the 2300 gas limit
     * imposed by `transfer`, making them unable to receive funds via
     * `transfer`. {sendValue} removes this limitation.
     *
     * https://diligence.consensys.net/posts/2019/09/stop-using-soliditys-transfer-now/[Learn more].
     *
     * IMPORTANT: because control is transferred to `recipient`, care must be
     * taken to not create reentrancy vulnerabilities. Consider using
     * {ReentrancyGuard} or the
     * https://solidity.readthedocs.io/en/v0.5.11/security-considerations.html#use-the-checks-effects-interactions-pattern[checks-effects-interactions pattern].
     */
    function sendValue(address payable recipient, uint256 amount) internal {
        require(address(this).balance >= amount, "Address: insufficient balance");

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

    /**
     * @dev Performs a Solidity function call using a low level `call`. A
     * plain `call` is an unsafe replacement for a function call: use this
     * function instead.
     *
     * If `target` reverts with a revert reason, it is bubbled up by this
     * function (like regular Solidity function calls).
     *
     * Returns the raw returned data. To convert to the expected return value,
     * use https://solidity.readthedocs.io/en/latest/units-and-global-variables.html?highlight=abi.decode#abi-encoding-and-decoding-functions[`abi.decode`].
     *
     * Requirements:
     *
     * - `target` must be a contract.
     * - calling `target` with `data` must not revert.
     *
     * _Available since v3.1._
     */
    function functionCall(address target, bytes memory data) internal returns (bytes memory) {
        return functionCall(target, data, "Address: low-level call failed");
    }

    /**
     * @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`], but with
     * `errorMessage` as a fallback revert reason when `target` reverts.
     *
     * _Available since v3.1._
     */
    function functionCall(
        address target,
        bytes memory data,
        string memory errorMessage
    ) internal returns (bytes memory) {
        return functionCallWithValue(target, data, 0, errorMessage);
    }

    /**
     * @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`],
     * but also transferring `value` wei to `target`.
     *
     * Requirements:
     *
     * - the calling contract must have an ETH balance of at least `value`.
     * - the called Solidity function must be `payable`.
     *
     * _Available since v3.1._
     */
    function functionCallWithValue(
        address target,
        bytes memory data,
        uint256 value
    ) internal returns (bytes memory) {
        return functionCallWithValue(target, data, value, "Address: low-level call with value failed");
    }

    /**
     * @dev Same as {xref-Address-functionCallWithValue-address-bytes-uint256-}[`functionCallWithValue`], but
     * with `errorMessage` as a fallback revert reason when `target` reverts.
     *
     * _Available since v3.1._
     */
    function functionCallWithValue(
        address target,
        bytes memory data,
        uint256 value,
        string memory errorMessage
    ) internal returns (bytes memory) {
        require(address(this).balance >= value, "Address: insufficient balance for call");
        require(isContract(target), "Address: call to non-contract");

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

    /**
     * @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`],
     * but performing a static call.
     *
     * _Available since v3.3._
     */
    function functionStaticCall(address target, bytes memory data) internal view returns (bytes memory) {
        return functionStaticCall(target, data, "Address: low-level static call failed");
    }

    /**
     * @dev Same as {xref-Address-functionCall-address-bytes-string-}[`functionCall`],
     * but performing a static call.
     *
     * _Available since v3.3._
     */
    function functionStaticCall(
        address target,
        bytes memory data,
        string memory errorMessage
    ) internal view returns (bytes memory) {
        require(isContract(target), "Address: static call to non-contract");

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

    /**
     * @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`],
     * but performing a delegate call.
     *
     * _Available since v3.4._
     */
    function functionDelegateCall(address target, bytes memory data) internal returns (bytes memory) {
        return functionDelegateCall(target, data, "Address: low-level delegate call failed");
    }

    /**
     * @dev Same as {xref-Address-functionCall-address-bytes-string-}[`functionCall`],
     * but performing a delegate call.
     *
     * _Available since v3.4._
     */
    function functionDelegateCall(
        address target,
        bytes memory data,
        string memory errorMessage
    ) internal returns (bytes memory) {
        require(isContract(target), "Address: delegate call to non-contract");

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

    /**
     * @dev Tool to verifies that a low level call was successful, and revert if it wasn't, either by bubbling the
     * revert reason using the provided one.
     *
     * _Available since v4.3._
     */
    function verifyCallResult(
        bool success,
        bytes memory returndata,
        string memory errorMessage
    ) internal pure returns (bytes memory) {
        if (success) {
            return returndata;
        } else {
            // Look for revert reason and bubble it up if present
            if (returndata.length > 0) {
                // The easiest way to bubble the revert reason is using memory via assembly
                /// @solidity memory-safe-assembly
                assembly {
                    let returndata_size := mload(returndata)
                    revert(add(32, returndata), returndata_size)
                }
            } else {
                revert(errorMessage);
            }
        }
    }
}

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



// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts v4.4.1 (utils/Context.sol)

pragma solidity ^0.8.0;

/**
 * @dev Provides information about the current execution context, including the
 * sender of the transaction and its data. While these are generally available
 * via msg.sender and msg.data, they should not be accessed in such a direct
 * manner, since when dealing with meta-transactions the account sending and
 * paying for execution may not be the actual sender (as far as an application
 * is concerned).
 *
 * This contract is only required for intermediate, library-like contracts.
 */
abstract contract Context {
    function _msgSender() internal view virtual returns (address) {
        return msg.sender;
    }

    function _msgData() internal view virtual returns (bytes calldata) {
        return msg.data;
    }
}

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



// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.7.0) (utils/Strings.sol)

pragma solidity ^0.8.0;

/**
 * @dev String operations.
 */
library Strings {
    bytes16 private constant _HEX_SYMBOLS = "0123456789abcdef";
    uint8 private constant _ADDRESS_LENGTH = 20;

    /**
     * @dev Converts a `uint256` to its ASCII `string` decimal representation.
     */
    function toString(uint256 value) internal pure returns (string memory) {
        // Inspired by OraclizeAPI's implementation - MIT licence
        // https://github.com/oraclize/ethereum-api/blob/b42146b063c7d6ee1358846c198246239e9360e8/oraclizeAPI_0.4.25.sol

        if (value == 0) {
            return "0";
        }
        uint256 temp = value;
        uint256 digits;
        while (temp != 0) {
            digits++;
            temp /= 10;
        }
        bytes memory buffer = new bytes(digits);
        while (value != 0) {
            digits -= 1;
            buffer[digits] = bytes1(uint8(48 + uint256(value % 10)));
            value /= 10;
        }
        return string(buffer);
    }

    /**
     * @dev Converts a `uint256` to its ASCII `string` hexadecimal representation.
     */
    function toHexString(uint256 value) internal pure returns (string memory) {
        if (value == 0) {
            return "0x00";
        }
        uint256 temp = value;
        uint256 length = 0;
        while (temp != 0) {
            length++;
            temp >>= 8;
        }
        return toHexString(value, length);
    }

    /**
     * @dev Converts a `uint256` to its ASCII `string` hexadecimal representation with fixed length.
     */
    function toHexString(uint256 value, uint256 length) internal pure returns (string memory) {
        bytes memory buffer = new bytes(2 * length + 2);
        buffer[0] = "0";
        buffer[1] = "x";
        for (uint256 i = 2 * length + 1; i > 1; --i) {
            buffer[i] = _HEX_SYMBOLS[value & 0xf];
            value >>= 4;
        }
        require(value == 0, "Strings: hex length insufficient");
        return string(buffer);
    }

    /**
     * @dev Converts an `address` with fixed length of 20 bytes to its not checksummed ASCII `string` hexadecimal representation.
     */
    function toHexString(address addr) internal pure returns (string memory) {
        return toHexString(uint256(uint160(addr)), _ADDRESS_LENGTH);
    }
}

// File: @openzeppelin/contracts/token/ERC20/IERC20.sol



// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.6.0) (token/ERC20/IERC20.sol)

pragma solidity ^0.8.0;

/**
 * @dev Interface of the ERC20 standard as defined in the EIP.
 */
interface IERC20 {
    /**
     * @dev Emitted when `value` tokens are moved from one account (`from`) to
     * another (`to`).
     *
     * Note that `value` may be zero.
     */
    event Transfer(address indexed from, address indexed to, uint256 value);

    /**
     * @dev Emitted when the allowance of a `spender` for an `owner` is set by
     * a call to {approve}. `value` is the new allowance.
     */
    event Approval(address indexed owner, address indexed spender, uint256 value);

    /**
     * @dev Returns the amount of tokens in existence.
     */
    function totalSupply() external view returns (uint256);

    /**
     * @dev Returns the amount of tokens owned by `account`.
     */
    function balanceOf(address account) external view returns (uint256);

    /**
     * @dev Moves `amount` tokens from the caller's account to `to`.
     *
     * Returns a boolean value indicating whether the operation succeeded.
     *
     * Emits a {Transfer} event.
     */
    function transfer(address to, uint256 amount) external returns (bool);

    /**
     * @dev Returns the remaining number of tokens that `spender` will be
     * allowed to spend on behalf of `owner` through {transferFrom}. This is
     * zero by default.
     *
     * This value changes when {approve} or {transferFrom} are called.
     */
    function allowance(address owner, address spender) external view returns (uint256);

    /**
     * @dev Sets `amount` as the allowance of `spender` over the caller's tokens.
     *
     * Returns a boolean value indicating whether the operation succeeded.
     *
     * IMPORTANT: Beware that changing an allowance with this method brings the risk
     * that someone may use both the old and the new allowance by unfortunate
     * transaction ordering. One possible solution to mitigate this race
     * condition is to first reduce the spender's allowance to 0 and set the
     * desired value afterwards:
     * https://github.com/ethereum/EIPs/issues/20#issuecomment-263524729
     *
     * Emits an {Approval} event.
     */
    function approve(address spender, uint256 amount) external returns (bool);

    /**
     * @dev Moves `amount` tokens from `from` to `to` using the
     * allowance mechanism. `amount` is then deducted from the caller's
     * allowance.
     *
     * Returns a boolean value indicating whether the operation succeeded.
     *
     * Emits a {Transfer} event.
     */
    function transferFrom(
        address from,
        address to,
        uint256 amount
    ) external returns (bool);
}

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



// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.7.0) (token/ERC721/IERC721.sol)

pragma solidity ^0.8.0;

import "../../utils/introspection/IERC165.sol";

/**
 * @dev Required interface of an ERC721 compliant contract.
 */
interface IERC721 is IERC165 {
    /**
     * @dev Emitted when `tokenId` token is transferred from `from` to `to`.
     */
    event Transfer(address indexed from, address indexed to, uint256 indexed tokenId);

    /**
     * @dev Emitted when `owner` enables `approved` to manage the `tokenId` token.
     */
    event Approval(address indexed owner, address indexed approved, uint256 indexed tokenId);

    /**
     * @dev Emitted when `owner` enables or disables (`approved`) `operator` to manage all of its assets.
     */
    event ApprovalForAll(address indexed owner, address indexed operator, bool approved);

    /**
     * @dev Returns the number of tokens in ``owner``'s account.
     */
    function balanceOf(address owner) external view returns (uint256 balance);

    /**
     * @dev Returns the owner of the `tokenId` token.
     *
     * Requirements:
     *
     * - `tokenId` must exist.
     */
    function ownerOf(uint256 tokenId) external view returns (address owner);

    /**
     * @dev Safely transfers `tokenId` token from `from` to `to`.
     *
     * Requirements:
     *
     * - `from` cannot be the zero address.
     * - `to` cannot be the zero address.
     * - `tokenId` token must exist and be owned by `from`.
     * - If the caller is not `from`, it must be approved to move this token by either {approve} or {setApprovalForAll}.
     * - If `to` refers to a smart contract, it must implement {IERC721Receiver-onERC721Received}, which is called upon a safe transfer.
     *
     * Emits a {Transfer} event.
     */
    function safeTransferFrom(
        address from,
        address to,
        uint256 tokenId,
        bytes calldata data
    ) external;

    /**
     * @dev Safely transfers `tokenId` token from `from` to `to`, checking first that contract recipients
     * are aware of the ERC721 protocol to prevent tokens from being forever locked.
     *
     * Requirements:
     *
     * - `from` cannot be the zero address.
     * - `to` cannot be the zero address.
     * - `tokenId` token must exist and be owned by `from`.
     * - If the caller is not `from`, it must have been allowed to move this token by either {approve} or {setApprovalForAll}.
     * - If `to` refers to a smart contract, it must implement {IERC721Receiver-onERC721Received}, which is called upon a safe transfer.
     *
     * Emits a {Transfer} event.
     */
    function safeTransferFrom(
        address from,
        address to,
        uint256 tokenId
    ) external;

    /**
     * @dev Transfers `tokenId` token from `from` to `to`.
     *
     * WARNING: Usage of this method is discouraged, use {safeTransferFrom} whenever possible.
     *
     * Requirements:
     *
     * - `from` cannot be the zero address.
     * - `to` cannot be the zero address.
     * - `tokenId` token must be owned by `from`.
     * - If the caller is not `from`, it must be approved to move this token by either {approve} or {setApprovalForAll}.
     *
     * Emits a {Transfer} event.
     */
    function transferFrom(
        address from,
        address to,
        uint256 tokenId
    ) external;

    /**
     * @dev Gives permission to `to` to transfer `tokenId` token to another account.
     * The approval is cleared when the token is transferred.
     *
     * Only a single account can be approved at a time, so approving the zero address clears previous approvals.
     *
     * Requirements:
     *
     * - The caller must own the token or be an approved operator.
     * - `tokenId` must exist.
     *
     * Emits an {Approval} event.
     */
    function approve(address to, uint256 tokenId) external;

    /**
     * @dev Approve or remove `operator` as an operator for the caller.
     * Operators can call {transferFrom} or {safeTransferFrom} for any token owned by the caller.
     *
     * Requirements:
     *
     * - The `operator` cannot be the caller.
     *
     * Emits an {ApprovalForAll} event.
     */
    function setApprovalForAll(address operator, bool _approved) external;

    /**
     * @dev Returns the account approved for `tokenId` token.
     *
     * Requirements:
     *
     * - `tokenId` must exist.
     */
    function getApproved(uint256 tokenId) external view returns (address operator);

    /**
     * @dev Returns if the `operator` is allowed to manage all of the assets of `owner`.
     *
     * See {setApprovalForAll}
     */
    function isApprovedForAll(address owner, address operator) external view returns (bool);
}

// File: @openzeppelin/contracts/access/Ownable.sol



// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.7.0) (access/Ownable.sol)

pragma solidity ^0.8.0;

import "../utils/Context.sol";

/**
 * @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: @openzeppelin/contracts/security/ReentrancyGuard.sol



// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts v4.4.1 (security/ReentrancyGuard.sol)

pragma solidity ^0.8.0;

/**
 * @dev Contract module that helps prevent reentrant calls to a function.
 *
 * Inheriting from `ReentrancyGuard` will make the {nonReentrant} modifier
 * available, which can be applied to functions to make sure there are no nested
 * (reentrant) calls to them.
 *
 * Note that because there is a single `nonReentrant` guard, functions marked as
 * `nonReentrant` may not call one another. This can be worked around by making
 * those functions `private`, and then adding `external` `nonReentrant` entry
 * points to them.
 *
 * TIP: If you would like to learn more about reentrancy and alternative ways
 * to protect against it, check out our blog post
 * https://blog.openzeppelin.com/reentrancy-after-istanbul/[Reentrancy After Istanbul].
 */
abstract contract ReentrancyGuard {
    // Booleans are more expensive than uint256 or any type that takes up a full
    // word because each write operation emits an extra SLOAD to first read the
    // slot's contents, replace the bits taken up by the boolean, and then write
    // back. This is the compiler's defense against contract upgrades and
    // pointer aliasing, and it cannot be disabled.

    // The values being non-zero value makes deployment a bit more expensive,
    // but in exchange the refund on every call to nonReentrant will be lower in
    // amount. Since refunds are capped to a percentage of the total
    // transaction's gas, it is best to keep them low in cases like this one, to
    // increase the likelihood of the full refund coming into effect.
    uint256 private constant _NOT_ENTERED = 1;
    uint256 private constant _ENTERED = 2;

    uint256 private _status;

    constructor() {
        _status = _NOT_ENTERED;
    }

    /**
     * @dev Prevents a contract from calling itself, directly or indirectly.
     * Calling a `nonReentrant` function from another `nonReentrant`
     * function is not supported. It is possible to prevent this from happening
     * by making the `nonReentrant` function external, and making it call a
     * `private` function that does the actual work.
     */
    modifier nonReentrant() {
        // On the first call to nonReentrant, _notEntered will be true
        require(_status != _ENTERED, "ReentrancyGuard: reentrant call");

        // Any calls to nonReentrant after this point will fail
        _status = _ENTERED;

        _;

        // By storing the original value once again, a refund is triggered (see
        // https://eips.ethereum.org/EIPS/eip-2200)
        _status = _NOT_ENTERED;
    }
}

// File: @openzeppelin/contracts/utils/cryptography/MerkleProof.sol



// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.7.0) (utils/cryptography/MerkleProof.sol)

pragma solidity ^0.8.0;

/**
 * @dev These functions deal with verification of Merkle Tree proofs.
 *
 * The proofs can be generated using the JavaScript library
 * https://github.com/miguelmota/merkletreejs[merkletreejs].
 * Note: the hashing algorithm should be keccak256 and pair sorting should be enabled.
 *
 * See `test/utils/cryptography/MerkleProof.test.js` for some examples.
 *
 * WARNING: You should avoid using leaf values that are 64 bytes long prior to
 * hashing, or use a hash function other than keccak256 for hashing leaves.
 * This is because the concatenation of a sorted pair of internal nodes in
 * the merkle tree could be reinterpreted as a leaf value.
 */
library MerkleProof {
    /**
     * @dev Returns true if a `leaf` can be proved to be a part of a Merkle tree
     * defined by `root`. For this, a `proof` must be provided, containing
     * sibling hashes on the branch from the leaf to the root of the tree. Each
     * pair of leaves and each pair of pre-images are assumed to be sorted.
     */
    function verify(
        bytes32[] memory proof,
        bytes32 root,
        bytes32 leaf
    ) internal pure returns (bool) {
        return processProof(proof, leaf) == root;
    }

    /**
     * @dev Calldata version of {verify}
     *
     * _Available since v4.7._
     */
    function verifyCalldata(
        bytes32[] calldata proof,
        bytes32 root,
        bytes32 leaf
    ) internal pure returns (bool) {
        return processProofCalldata(proof, leaf) == root;
    }

    /**
     * @dev Returns the rebuilt hash obtained by traversing a Merkle tree up
     * from `leaf` using `proof`. A `proof` is valid if and only if the rebuilt
     * hash matches the root of the tree. When processing the proof, the pairs
     * of leafs & pre-images are assumed to be sorted.
     *
     * _Available since v4.4._
     */
    function processProof(bytes32[] memory proof, bytes32 leaf) internal pure returns (bytes32) {
        bytes32 computedHash = leaf;
        for (uint256 i = 0; i < proof.length; i++) {
            computedHash = _hashPair(computedHash, proof[i]);
        }
        return computedHash;
    }

    /**
     * @dev Calldata version of {processProof}
     *
     * _Available since v4.7._
     */
    function processProofCalldata(bytes32[] calldata proof, bytes32 leaf) internal pure returns (bytes32) {
        bytes32 computedHash = leaf;
        for (uint256 i = 0; i < proof.length; i++) {
            computedHash = _hashPair(computedHash, proof[i]);
        }
        return computedHash;
    }

    /**
     * @dev Returns true if the `leaves` can be proved to be a part of a Merkle tree defined by
     * `root`, according to `proof` and `proofFlags` as described in {processMultiProof}.
     *
     * _Available since v4.7._
     */
    function multiProofVerify(
        bytes32[] memory proof,
        bool[] memory proofFlags,
        bytes32 root,
        bytes32[] memory leaves
    ) internal pure returns (bool) {
        return processMultiProof(proof, proofFlags, leaves) == root;
    }

    /**
     * @dev Calldata version of {multiProofVerify}
     *
     * _Available since v4.7._
     */
    function multiProofVerifyCalldata(
        bytes32[] calldata proof,
        bool[] calldata proofFlags,
        bytes32 root,
        bytes32[] memory leaves
    ) internal pure returns (bool) {
        return processMultiProofCalldata(proof, proofFlags, leaves) == root;
    }

    /**
     * @dev Returns the root of a tree reconstructed from `leaves` and the sibling nodes in `proof`,
     * consuming from one or the other at each step according to the instructions given by
     * `proofFlags`.
     *
     * _Available since v4.7._
     */
    function processMultiProof(
        bytes32[] memory proof,
        bool[] memory proofFlags,
        bytes32[] memory leaves
    ) internal pure returns (bytes32 merkleRoot) {
        // This function rebuild the root hash by traversing the tree up from the leaves. The root is rebuilt by
        // consuming and producing values on a queue. The queue starts with the `leaves` array, then goes onto the
        // `hashes` array. At the end of the process, the last hash in the `hashes` array should contain the root of
        // the merkle tree.
        uint256 leavesLen = leaves.length;
        uint256 totalHashes = proofFlags.length;

        // Check proof validity.
        require(leavesLen + proof.length - 1 == totalHashes, "MerkleProof: invalid multiproof");

        // The xxxPos values are "pointers" to the next value to consume in each array. All accesses are done using
        // `xxx[xxxPos++]`, which return the current value and increment the pointer, thus mimicking a queue's "pop".
        bytes32[] memory hashes = new bytes32[](totalHashes);
        uint256 leafPos = 0;
        uint256 hashPos = 0;
        uint256 proofPos = 0;
        // At each step, we compute the next hash using two values:
        // - a value from the "main queue". If not all leaves have been consumed, we get the next leaf, otherwise we
        //   get the next hash.
        // - depending on the flag, either another value for the "main queue" (merging branches) or an element from the
        //   `proof` array.
        for (uint256 i = 0; i < totalHashes; i++) {
            bytes32 a = leafPos < leavesLen ? leaves[leafPos++] : hashes[hashPos++];
            bytes32 b = proofFlags[i] ? leafPos < leavesLen ? leaves[leafPos++] : hashes[hashPos++] : proof[proofPos++];
            hashes[i] = _hashPair(a, b);
        }

        if (totalHashes > 0) {
            return hashes[totalHashes - 1];
        } else if (leavesLen > 0) {
            return leaves[0];
        } else {
            return proof[0];
        }
    }

    /**
     * @dev Calldata version of {processMultiProof}
     *
     * _Available since v4.7._
     */
    function processMultiProofCalldata(
        bytes32[] calldata proof,
        bool[] calldata proofFlags,
        bytes32[] memory leaves
    ) internal pure returns (bytes32 merkleRoot) {
        // This function rebuild the root hash by traversing the tree up from the leaves. The root is rebuilt by
        // consuming and producing values on a queue. The queue starts with the `leaves` array, then goes onto the
        // `hashes` array. At the end of the process, the last hash in the `hashes` array should contain the root of
        // the merkle tree.
        uint256 leavesLen = leaves.length;
        uint256 totalHashes = proofFlags.length;

        // Check proof validity.
        require(leavesLen + proof.length - 1 == totalHashes, "MerkleProof: invalid multiproof");

        // The xxxPos values are "pointers" to the next value to consume in each array. All accesses are done using
        // `xxx[xxxPos++]`, which return the current value and increment the pointer, thus mimicking a queue's "pop".
        bytes32[] memory hashes = new bytes32[](totalHashes);
        uint256 leafPos = 0;
        uint256 hashPos = 0;
        uint256 proofPos = 0;
        // At each step, we compute the next hash using two values:
        // - a value from the "main queue". If not all leaves have been consumed, we get the next leaf, otherwise we
        //   get the next hash.
        // - depending on the flag, either another value for the "main queue" (merging branches) or an element from the
        //   `proof` array.
        for (uint256 i = 0; i < totalHashes; i++) {
            bytes32 a = leafPos < leavesLen ? leaves[leafPos++] : hashes[hashPos++];
            bytes32 b = proofFlags[i] ? leafPos < leavesLen ? leaves[leafPos++] : hashes[hashPos++] : proof[proofPos++];
            hashes[i] = _hashPair(a, b);
        }

        if (totalHashes > 0) {
            return hashes[totalHashes - 1];
        } else if (leavesLen > 0) {
            return leaves[0];
        } else {
            return proof[0];
        }
    }

    function _hashPair(bytes32 a, bytes32 b) private pure returns (bytes32) {
        return a < b ? _efficientHash(a, b) : _efficientHash(b, a);
    }

    function _efficientHash(bytes32 a, bytes32 b) private pure returns (bytes32 value) {
        /// @solidity memory-safe-assembly
        assembly {
            mstore(0x00, a)
            mstore(0x20, b)
            value := keccak256(0x00, 0x40)
        }
    }
}

// File: contracts/ERC721AQueryable.sol



// SPDX-License-Identifier: MIT
// ERC721A Contracts v4.1.0
// Creator: Chiru Labs

pragma solidity ^0.8.15;

import "./ERC721A.sol";

interface IERC721AQueryable is IERC721A {
	/**
	 * Invalid query range (`start` >= `stop`).
	 */
	error InvalidQueryRange();

	/**
	 * @dev Returns the `TokenOwnership` struct at `tokenId` without reverting.
	 *
	 * If the `tokenId` is out of bounds:
	 *   - `addr` = `address(0)`
	 *   - `startTimestamp` = `0`
	 *   - `burned` = `false`
	 *
	 * If the `tokenId` is burned:
	 *   - `addr` = `<Address of owner before token was burned>`
	 *   - `startTimestamp` = `<Timestamp when token was burned>`
	 *   - `burned = `true`
	 *
	 * Otherwise:
	 *   - `addr` = `<Address of owner>`
	 *   - `startTimestamp` = `<Timestamp of start of ownership>`
	 *   - `burned = `false`
	 */
	function explicitOwnershipOf(uint256 tokenId) external view returns (TokenOwnership memory);

	/**
	 * @dev Returns an array of `TokenOwnership` structs at `tokenIds` in order.
	 * See {ERC721AQueryable-explicitOwnershipOf}
	 */
	function explicitOwnershipsOf(uint256[] memory tokenIds)
		external
		view
		returns (TokenOwnership[] memory);

	/**
	 * @dev Returns an array of token IDs owned by `owner`,
	 * in the range [`start`, `stop`)
	 * (i.e. `start <= tokenId < stop`).
	 *
	 * This function allows for tokens to be queried if the collection
	 * grows too big for a single call of {ERC721AQueryable-tokensOfOwner}.
	 *
	 * Requirements:
	 *
	 * - `start` < `stop`
	 */
	function tokensOfOwnerIn(
		address owner,
		uint256 start,
		uint256 stop
	) external view returns (uint256[] memory);

	/**
	 * @dev Returns an array of token IDs owned by `owner`.
	 *
	 * This function scans the ownership mapping and is O(totalSupply) in complexity.
	 * It is meant to be called off-chain.
	 *
	 * See {ERC721AQueryable-tokensOfOwnerIn} for splitting the scan into
	 * multiple smaller scans if the collection is large enough to cause
	 * an out-of-gas error (10K pfp collections should be fine).
	 */
	function tokensOfOwner(address owner) external view returns (uint256[] memory);
}

/**
 * @title ERC721A Queryable
 * @dev ERC721A subclass with convenience query functions.
 */
abstract contract ERC721AQueryable is ERC721A, IERC721AQueryable {
	/**
	 * @dev Returns the `TokenOwnership` struct at `tokenId` without reverting.
	 *
	 * If the `tokenId` is out of bounds:
	 *   - `addr` = `address(0)`
	 *   - `startTimestamp` = `0`
	 *   - `burned` = `false`
	 *   - `extraData` = `0`
	 *
	 * If the `tokenId` is burned:
	 *   - `addr` = `<Address of owner before token was burned>`
	 *   - `startTimestamp` = `<Timestamp when token was burned>`
	 *   - `burned = `true`
	 *   - `extraData` = `<Extra data when token was burned>`
	 *
	 * Otherwise:
	 *   - `addr` = `<Address of owner>`
	 *   - `startTimestamp` = `<Timestamp of start of ownership>`
	 *   - `burned = `false`
	 *   - `extraData` = `<Extra data at start of ownership>`
	 */
	function explicitOwnershipOf(uint256 tokenId)
		public
		view
		override
		returns (TokenOwnership memory)
	{
		TokenOwnership memory ownership;
		if (tokenId < _startTokenId() || tokenId >= _nextTokenId()) {
			return ownership;
		}
		ownership = _ownershipAt(tokenId);
		if (ownership.burned) {
			return ownership;
		}
		return _ownershipOf(tokenId);
	}

	/**
	 * @dev Returns an array of `TokenOwnership` structs at `tokenIds` in order.
	 * See {ERC721AQueryable-explicitOwnershipOf}
	 */
	function explicitOwnershipsOf(uint256[] memory tokenIds)
		external
		view
		override
		returns (TokenOwnership[] memory)
	{
		unchecked {
			uint256 tokenIdsLength = tokenIds.length;
			TokenOwnership[] memory ownerships = new TokenOwnership[](tokenIdsLength);
			for (uint256 i; i != tokenIdsLength; ++i) {
				ownerships[i] = explicitOwnershipOf(tokenIds[i]);
			}
			return ownerships;
		}
	}

	/**
	 * @dev Returns an array of token IDs owned by `owner`,
	 * in the range [`start`, `stop`)
	 * (i.e. `start <= tokenId < stop`).
	 *
	 * This function allows for tokens to be queried if the collection
	 * grows too big for a single call of {ERC721AQueryable-tokensOfOwner}.
	 *
	 * Requirements:
	 *
	 * - `start` < `stop`
	 */
	function tokensOfOwnerIn(
		address owner,
		uint256 start,
		uint256 stop
	) external view override returns (uint256[] memory) {
		unchecked {
			if (start >= stop) revert InvalidQueryRange();
			uint256 tokenIdsIdx;
			uint256 stopLimit = _nextTokenId();
			// Set `start = max(start, _startTokenId())`.
			if (start < _startTokenId()) {
				start = _startTokenId();
			}
			// Set `stop = min(stop, stopLimit)`.
			if (stop > stopLimit) {
				stop = stopLimit;
			}
			uint256 tokenIdsMaxLength = balanceOf(owner);
			// Set `tokenIdsMaxLength = min(balanceOf(owner), stop - start)`,
			// to cater for cases where `balanceOf(owner)` is too big.
			if (start < stop) {
				uint256 rangeLength = stop - start;
				if (rangeLength < tokenIdsMaxLength) {
					tokenIdsMaxLength = rangeLength;
				}
			} else {
				tokenIdsMaxLength = 0;
			}
			uint256[] memory tokenIds = new uint256[](tokenIdsMaxLength);
			if (tokenIdsMaxLength == 0) {
				return tokenIds;
			}
			// We need to call `explicitOwnershipOf(start)`,
			// because the slot at `start` may not be initialized.
			TokenOwnership memory ownership = explicitOwnershipOf(start);
			address currOwnershipAddr;
			// If the starting slot exists (i.e. not burned), initialize `currOwnershipAddr`.
			// `ownership.address` will not be zero, as `start` is clamped to the valid token ID range.
			if (!ownership.burned) {
				currOwnershipAddr = ownership.addr;
			}
			for (uint256 i = start; i != stop && tokenIdsIdx != tokenIdsMaxLength; ++i) {
				ownership = _ownershipAt(i);
				if (ownership.burned) {
					continue;
				}
				if (ownership.addr != address(0)) {
					currOwnershipAddr = ownership.addr;
				}
				if (currOwnershipAddr == owner) {
					tokenIds[tokenIdsIdx++] = i;
				}
			}
			// Downsize the array to fit.
			assembly {
				mstore(tokenIds, tokenIdsIdx)
			}
			return tokenIds;
		}
	}

	/**
	 * @dev Returns an array of token IDs owned by `owner`.
	 *
	 * This function scans the ownership mapping and is O(totalSupply) in complexity.
	 * It is meant to be called off-chain.
	 *
	 * See {ERC721AQueryable-tokensOfOwnerIn} for splitting the scan into
	 * multiple smaller scans if the collection is large enough to cause
	 * an out-of-gas error (10K pfp collections should be fine).
	 */
	function tokensOfOwner(address owner) external view override 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;
		}
	}
}

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



// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts v4.4.1 (utils/introspection/IERC165.sol)

pragma solidity ^0.8.0;

/**
 * @dev Interface of the ERC165 standard, as defined in the
 * https://eips.ethereum.org/EIPS/eip-165[EIP].
 *
 * Implementers can declare support of contract interfaces, which can then be
 * queried by others ({ERC165Checker}).
 *
 * For an implementation, see {ERC165}.
 */
interface IERC165 {
    /**
     * @dev Returns true if this contract implements the interface defined by
     * `interfaceId`. See the corresponding
     * https://eips.ethereum.org/EIPS/eip-165#how-interfaces-are-identified[EIP section]
     * to learn more about how these ids are created.
     *
     * This function call must use less than 30 000 gas.
     */
    function supportsInterface(bytes4 interfaceId) external view returns (bool);
}

// File: contracts/ERC721A.sol



// SPDX-License-Identifier: MIT
// ERC721A Contracts v4.1.0
// Creator: Chiru Labs

pragma solidity ^0.8.15;

/**
 * @dev Interface of an ERC721A compliant contract.
 */
interface IERC721A {
	/**
	 * The caller must own the token or be an approved operator.
	 */
	error ApprovalCallerNotOwnerNorApproved();

	/**
	 * The token does not exist.
	 */
	error ApprovalQueryForNonexistentToken();

	/**
	 * The caller cannot approve to their own address.
	 */
	error ApproveToCaller();

	/**
	 * 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();

	struct TokenOwnership {
		// The address of the owner.
		address addr;
		// Keeps track of the start time of ownership with minimal overhead for tokenomics.
		uint64 startTimestamp;
		// Whether the token has been burned.
		bool burned;
		// Arbitrary data similar to `startTimestamp` that can be set through `_extraData`.
		uint24 extraData;
	}

	/**
	 * @dev Returns the total amount of tokens stored by the contract.
	 *
	 * Burned tokens are calculated here, use `_totalMinted()` if you want to count just minted tokens.
	 */
	function totalSupply() external view returns (uint256);

	// ==============================
	//            IERC165
	// ==============================

	/**
	 * @dev Returns true if this contract implements the interface defined by
	 * `interfaceId`. See the corresponding
	 * https://eips.ethereum.org/EIPS/eip-165#how-interfaces-are-identified[EIP section]
	 * to learn more about how these ids are created.
	 *
	 * This function call must use less than 30 000 gas.
	 */
	function supportsInterface(bytes4 interfaceId) external view returns (bool);

	// ==============================
	//            IERC721
	// ==============================

	/**
	 * @dev Emitted when `tokenId` token is transferred from `from` to `to`.
	 */
	event Transfer(address indexed from, address indexed to, uint256 indexed tokenId);

	/**
	 * @dev Emitted when `owner` enables `approved` to manage the `tokenId` token.
	 */
	event Approval(address indexed owner, address indexed approved, uint256 indexed tokenId);

	/**
	 * @dev Emitted when `owner` enables or disables (`approved`) `operator` to manage all of its assets.
	 */
	event ApprovalForAll(address indexed owner, address indexed operator, bool approved);

	/**
	 * @dev Returns the number of tokens in ``owner``'s account.
	 */
	function balanceOf(address owner) external view returns (uint256 balance);

	/**
	 * @dev Returns the owner of the `tokenId` token.
	 *
	 * Requirements:
	 *
	 * - `tokenId` must exist.
	 */
	function ownerOf(uint256 tokenId) external view returns (address owner);

	/**
	 * @dev Safely transfers `tokenId` token from `from` to `to`.
	 *
	 * Requirements:
	 *
	 * - `from` cannot be the zero address.
	 * - `to` cannot be the zero address.
	 * - `tokenId` token must exist and be owned by `from`.
	 * - If the caller is not `from`, it must be approved to move this token by either {approve} or {setApprovalForAll}.
	 * - If `to` refers to a smart contract, it must implement {IERC721Receiver-onERC721Received}, which is called upon a safe transfer.
	 *
	 * Emits a {Transfer} event.
	 */
	function safeTransferFrom(
		address from,
		address to,
		uint256 tokenId,
		bytes calldata data
	) external;

	/**
	 * @dev Safely transfers `tokenId` token from `from` to `to`, checking first that contract recipients
	 * are aware of the ERC721 protocol to prevent tokens from being forever locked.
	 *
	 * Requirements:
	 *
	 * - `from` cannot be the zero address.
	 * - `to` cannot be the zero address.
	 * - `tokenId` token must exist and be owned by `from`.
	 * - If the caller is not `from`, it must be have been allowed to move this token by either {approve} or {setApprovalForAll}.
	 * - If `to` refers to a smart contract, it must implement {IERC721Receiver-onERC721Received}, which is called upon a safe transfer.
	 *
	 * Emits a {Transfer} event.
	 */
	function safeTransferFrom(
		address from,
		address to,
		uint256 tokenId
	) external;

	/**
	 * @dev Transfers `tokenId` token from `from` to `to`.
	 *
	 * WARNING: Usage of this method is discouraged, use {safeTransferFrom} whenever possible.
	 *
	 * Requirements:
	 *
	 * - `from` cannot be the zero address.
	 * - `to` cannot be the zero address.
	 * - `tokenId` token must be owned by `from`.
	 * - If the caller is not `from`, it must be approved to move this token by either {approve} or {setApprovalForAll}.
	 *
	 * Emits a {Transfer} event.
	 */
	function transferFrom(
		address from,
		address to,
		uint256 tokenId
	) external;

	/**
	 * @dev Gives permission to `to` to transfer `tokenId` token to another account.
	 * The approval is cleared when the token is transferred.
	 *
	 * Only a single account can be approved at a time, so approving the zero address clears previous approvals.
	 *
	 * Requirements:
	 *
	 * - The caller must own the token or be an approved operator.
	 * - `tokenId` must exist.
	 *
	 * Emits an {Approval} event.
	 */
	function approve(address to, uint256 tokenId) external;

	/**
	 * @dev Approve or remove `operator` as an operator for the caller.
	 * Operators can call {transferFrom} or {safeTransferFrom} for any token owned by the caller.
	 *
	 * Requirements:
	 *
	 * - The `operator` cannot be the caller.
	 *
	 * Emits an {ApprovalForAll} event.
	 */
	function setApprovalForAll(address operator, bool _approved) external;

	/**
	 * @dev Returns the account approved for `tokenId` token.
	 *
	 * Requirements:
	 *
	 * - `tokenId` must exist.
	 */
	function getApproved(uint256 tokenId) external view returns (address operator);

	/**
	 * @dev Returns if the `operator` is allowed to manage all of the assets of `owner`.
	 *
	 * See {setApprovalForAll}
	 */
	function isApprovedForAll(address owner, address operator) external view returns (bool);

	// ==============================
	//        IERC721Metadata
	// ==============================

	/**
	 * @dev Returns the token collection name.
	 */
	function name() external view returns (string memory);

	/**
	 * @dev Returns the token collection symbol.
	 */
	function symbol() external view returns (string memory);

	/**
	 * @dev Returns the Uniform Resource Identifier (URI) for `tokenId` token.
	 */
	function tokenURI(uint256 tokenId) external view returns (string memory);

	// ==============================
	//            IERC2309
	// ==============================

	/**
	 * @dev Emitted when tokens in `fromTokenId` to `toTokenId` (inclusive) is transferred from `from` to `to`,
	 * as defined in the ERC2309 standard. See `_mintERC2309` for more details.
	 */
	event ConsecutiveTransfer(
		uint256 indexed fromTokenId,
		uint256 toTokenId,
		address indexed from,
		address indexed to
	);
}

/**
 * @dev ERC721 token receiver interface.
 */
interface ERC721A__IERC721Receiver {
	function onERC721Received(
		address operator,
		address from,
		uint256 tokenId,
		bytes calldata data
	) external returns (bytes4);
}

/**
 * @dev Implementation of https://eips.ethereum.org/EIPS/eip-721[ERC721] Non-Fungible Token Standard,
 * including the Metadata extension. Built to optimize for lower gas during batch mints.
 *
 * Assumes serials are sequentially minted starting at `_startTokenId()`
 * (defaults to 0, e.g. 0, 1, 2, 3..).
 *
 * Assumes that an owner cannot have more than 2**64 - 1 (max value of uint64) of supply.
 *
 * Assumes that the maximum token id cannot exceed 2**256 - 1 (max value of uint256).
 */
contract ERC721A is IERC721A {
	// Mask of an entry in packed address data.
	uint256 private constant BITMASK_ADDRESS_DATA_ENTRY = (1 << 64) - 1;

	// The bit position of `numberMinted` in packed address data.
	uint256 private constant BITPOS_NUMBER_MINTED = 64;

	// The bit position of `numberBurned` in packed address data.
	uint256 private constant BITPOS_NUMBER_BURNED = 128;

	// The bit position of `aux` in packed address data.
	uint256 private constant BITPOS_AUX = 192;

	// Mask of all 256 bits in packed address data except the 64 bits for `aux`.
	uint256 private constant BITMASK_AUX_COMPLEMENT = (1 << 192) - 1;

	// The bit position of `startTimestamp` in packed ownership.
	uint256 private constant BITPOS_START_TIMESTAMP = 160;

	// The bit mask of the `burned` bit in packed ownership.
	uint256 private constant BITMASK_BURNED = 1 << 224;

	// The bit position of the `nextInitialized` bit in packed ownership.
	uint256 private constant BITPOS_NEXT_INITIALIZED = 225;

	// The bit mask of the `nextInitialized` bit in packed ownership.
	uint256 private constant BITMASK_NEXT_INITIALIZED = 1 << 225;

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

	// The number of tokens burned.
	uint256 private _burnCounter;

	// Token name
	string private _name;

	// Token symbol
	string private _symbol;

	// Mapping from token ID to ownership details
	// An empty struct value does not necessarily mean the token is unowned.
	// See `_packedOwnershipOf` implementation for details.
	//
	// Bits Layout:
	// - [0..159]   `addr`
	// - [160..223] `startTimestamp`
	// - [224]      `burned`
	// - [225]      `nextInitialized`
	// - [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 => address) private _tokenApprovals;

	// Mapping from owner to operator approvals
	mapping(address => mapping(address => bool)) private _operatorApprovals;

	constructor(string memory name_, string memory symbol_) {
		_name = name_;
		_symbol = symbol_;
		_currentIndex = _startTokenId();
	}

	/**
	 * @dev Returns the starting token ID.
	 * To change the starting token ID, please override this function.
	 */
	function _startTokenId() internal view virtual returns (uint256) {
		return 0;
	}

	/**
	 * @dev Returns the next token ID to be minted.
	 */
	function _nextTokenId() internal view returns (uint256) {
		return _currentIndex;
	}

	/**
	 * @dev Returns the total number of tokens in existence.
	 * Burned tokens will reduce the count.
	 * To get the total number of tokens minted, please see `_totalMinted`.
	 */
	function totalSupply() public view override returns (uint256) {
		// Counter underflow is impossible as _burnCounter cannot be incremented
		// more than `_currentIndex - _startTokenId()` times.
		unchecked {
			return _currentIndex - _burnCounter - _startTokenId();
		}
	}

	/**
	 * @dev Returns the total amount of tokens minted in the contract.
	 */
	function _totalMinted() internal view returns (uint256) {
		// Counter underflow is impossible as _currentIndex does not decrement,
		// and it is initialized to `_startTokenId()`
		unchecked {
			return _currentIndex - _startTokenId();
		}
	}

	/**
	 * @dev Returns the total number of tokens burned.
	 */
	function _totalBurned() internal view returns (uint256) {
		return _burnCounter;
	}

	/**
	 * @dev See {IERC165-supportsInterface}.
	 */
	function supportsInterface(bytes4 interfaceId) public view virtual override returns (bool) {
		// The interface IDs are constants representing the first 4 bytes of the XOR of
		// all function selectors in the interface. See: https://eips.ethereum.org/EIPS/eip-165
		// e.g. `bytes4(i.functionA.selector ^ i.functionB.selector ^ ...)`
		return
			interfaceId == 0x01ffc9a7 || // ERC165 interface ID for ERC165.
			interfaceId == 0x80ac58cd || // ERC165 interface ID for ERC721.
			interfaceId == 0x5b5e139f; // ERC165 interface ID for ERC721Metadata.
	}

	/**
	 * @dev See {IERC721-balanceOf}.
	 */
	function balanceOf(address owner) public view override returns (uint256) {
		if (owner == address(0)) revert BalanceQueryForZeroAddress();
		return _packedAddressData[owner] & BITMASK_ADDRESS_DATA_ENTRY;
	}

	/**
	 * Returns the number of tokens minted by `owner`.
	 */
	function _numberMinted(address owner) internal view returns (uint256) {
		return (_packedAddressData[owner] >> BITPOS_NUMBER_MINTED) & BITMASK_ADDRESS_DATA_ENTRY;
	}

	/**
	 * Returns the number of tokens burned by or on behalf of `owner`.
	 */
	function _numberBurned(address owner) internal view returns (uint256) {
		return (_packedAddressData[owner] >> BITPOS_NUMBER_BURNED) & BITMASK_ADDRESS_DATA_ENTRY;
	}

	/**
	 * Returns the 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 {
		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;
	}

	/**
	 * Returns the packed ownership data of `tokenId`.
	 */
	function _packedOwnershipOf(uint256 tokenId) private view returns (uint256) {
		uint256 curr = tokenId;

		unchecked {
			if (_startTokenId() <= curr)
				if (curr < _currentIndex) {
					uint256 packed = _packedOwnerships[curr];
					// If not burned.
					if (packed & BITMASK_BURNED == 0) {
						// Invariant:
						// There will always be an ownership that has an address and is not burned
						// before an ownership that does not have an address and is not burned.
						// Hence, curr will not underflow.
						//
						// We can directly compare the packed value.
						// If the address is zero, packed is zero.
						while (packed == 0) {
							packed = _packedOwnerships[--curr];
						}
						return packed;
					}
				}
		}
		revert OwnerQueryForNonexistentToken();
	}

	/**
	 * Returns the unpacked `TokenOwnership` struct from `packed`.
	 */
	function _unpackedOwnership(uint256 packed)
		private
		pure
		returns (TokenOwnership memory ownership)
	{
		ownership.addr = address(uint160(packed));
		ownership.startTimestamp = uint64(packed >> BITPOS_START_TIMESTAMP);
		ownership.burned = packed & BITMASK_BURNED != 0;
		ownership.extraData = uint24(packed >> BITPOS_EXTRA_DATA);
	}

	/**
	 * Returns the unpacked `TokenOwnership` struct at `index`.
	 */
	function _ownershipAt(uint256 index) internal view returns (TokenOwnership memory) {
		return _unpackedOwnership(_packedOwnerships[index]);
	}

	/**
	 * @dev Initializes the ownership slot minted at `index` for efficiency purposes.
	 */
	function _initializeOwnershipAt(uint256 index) internal {
		if (_packedOwnerships[index] == 0) {
			_packedOwnerships[index] = _packedOwnershipOf(index);
		}
	}

	/**
	 * Gas spent here starts off proportional to the maximum mint batch size.
	 * It gradually moves to O(1) as tokens get transferred around in the collection over time.
	 */
	function _ownershipOf(uint256 tokenId) internal view returns (TokenOwnership memory) {
		return _unpackedOwnership(_packedOwnershipOf(tokenId));
	}

	/**
	 * @dev 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 See {IERC721-ownerOf}.
	 */
	function ownerOf(uint256 tokenId) public view override returns (address) {
		return address(uint160(_packedOwnershipOf(tokenId)));
	}

	/**
	 * @dev See {IERC721Metadata-name}.
	 */
	function name() public view virtual override returns (string memory) {
		return _name;
	}

	/**
	 * @dev See {IERC721Metadata-symbol}.
	 */
	function symbol() public view virtual override returns (string memory) {
		return _symbol;
	}

	/**
	 * @dev See {IERC721Metadata-tokenURI}.
	 */
	function tokenURI(uint256 tokenId) public view virtual override returns (string memory) {
		if (!_exists(tokenId)) revert URIQueryForNonexistentToken();

		string memory baseURI = _baseURI();
		return bytes(baseURI).length != 0 ? string(abi.encodePacked(baseURI, _toString(tokenId))) : "";
	}

	/**
	 * @dev Base URI for computing {tokenURI}. If set, the resulting URI for each
	 * token will be the concatenation of the `baseURI` and the `tokenId`. Empty
	 * by default, it can be overridden in child contracts.
	 */
	function _baseURI() internal view virtual returns (string memory) {
		return "";
	}

	/**
	 * @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))
		}
	}

	/**
	 * @dev See {IERC721-approve}.
	 */
	function approve(address to, uint256 tokenId) public override {
		address owner = ownerOf(tokenId);

		if (_msgSenderERC721A() != owner)
			if (!isApprovedForAll(owner, _msgSenderERC721A())) {
				revert ApprovalCallerNotOwnerNorApproved();
			}

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

	/**
	 * @dev See {IERC721-getApproved}.
	 */
	function getApproved(uint256 tokenId) public view override returns (address) {
		if (!_exists(tokenId)) revert ApprovalQueryForNonexistentToken();

		return _tokenApprovals[tokenId];
	}

	/**
	 * @dev See {IERC721-setApprovalForAll}.
	 */
	function setApprovalForAll(address operator, bool approved) public virtual override {
		if (operator == _msgSenderERC721A()) revert ApproveToCaller();

		_operatorApprovals[_msgSenderERC721A()][operator] = approved;
		emit ApprovalForAll(_msgSenderERC721A(), operator, approved);
	}

	/**
	 * @dev See {IERC721-isApprovedForAll}.
	 */
	function isApprovedForAll(address owner, address operator)
		public
		view
		virtual
		override
		returns (bool)
	{
		return _operatorApprovals[owner][operator];
	}

	/**
	 * @dev See {IERC721-safeTransferFrom}.
	 */
	function safeTransferFrom(
		address from,
		address to,
		uint256 tokenId
	) public virtual override {
		safeTransferFrom(from, to, tokenId, "");
	}

	/**
	 * @dev See {IERC721-safeTransferFrom}.
	 */
	function safeTransferFrom(
		address from,
		address to,
		uint256 tokenId,
		bytes memory _data
	) public virtual override {
		transferFrom(from, to, tokenId);
		if (to.code.length != 0)
			if (!_checkContractOnERC721Received(from, to, tokenId, _data)) {
				revert TransferToNonERC721ReceiverImplementer();
			}
	}

	/**
	 * @dev Returns whether `tokenId` exists.
	 *
	 * Tokens can be managed by their owner or approved accounts via {approve} or {setApprovalForAll}.
	 *
	 * Tokens start existing when they are minted (`_mint`),
	 */
	function _exists(uint256 tokenId) internal view returns (bool) {
		return
			_startTokenId() <= tokenId &&
			tokenId < _currentIndex && // If within bounds,
			_packedOwnerships[tokenId] & BITMASK_BURNED == 0; // and not burned.
	}

	/**
	 * @dev Equivalent to `_safeMint(to, quantity, '')`.
	 */
	function _safeMint(address to, uint256 quantity) internal {
		_safeMint(to, quantity, "");
	}

	/**
	 * @dev Safely mints `quantity` tokens and transfers them to `to`.
	 *
	 * Requirements:
	 *
	 * - If `to` refers to a smart contract, it must implement
	 *   {IERC721Receiver-onERC721Received}, which is called for each safe transfer.
	 * - `quantity` must be greater than 0.
	 *
	 * See {_mint}.
	 *
	 * Emits a {Transfer} event for each mint.
	 */
	function _safeMint(
		address to,
		uint256 quantity,
		bytes memory _data
	) internal {
		_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 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 {
		uint256 startTokenId = _currentIndex;
		if (to == address(0)) revert MintToZeroAddress();
		if (quantity == 0) revert MintZeroQuantity();

		_beforeTokenTransfers(address(0), to, startTokenId, quantity);

		// Overflows are incredibly unrealistic.
		// `balance` 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 tokenId = startTokenId;
			uint256 end = startTokenId + quantity;
			do {
				emit Transfer(address(0), to, tokenId++);
			} while (tokenId < end);

			_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 {
		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 Returns the storage slot and value for the approved address of `tokenId`.
	 */
	function _getApprovedAddress(uint256 tokenId)
		private
		view
		returns (uint256 approvedAddressSlot, address approvedAddress)
	{
		mapping(uint256 => address) storage tokenApprovalsPtr = _tokenApprovals;
		// The following is equivalent to `approvedAddress = _tokenApprovals[tokenId]`.
		assembly {
			// Compute the slot.
			mstore(0x00, tokenId)
			mstore(0x20, tokenApprovalsPtr.slot)
			approvedAddressSlot := keccak256(0x00, 0x40)
			// Load the slot's value from storage.
			approvedAddress := sload(approvedAddressSlot)
		}
	}

	/**
	 * @dev Returns whether the `approvedAddress` is equals to `from` or `msgSender`.
	 */
	function _isOwnerOrApproved(
		address approvedAddress,
		address from,
		address msgSender
	) private pure returns (bool result) {
		assembly {
			// Mask `from` to the lower 160 bits, in case the upper bits somehow aren't clean.
			from := and(from, BITMASK_ADDRESS)
			// Mask `msgSender` to the lower 160 bits, in case the upper bits somehow aren't clean.
			msgSender := and(msgSender, BITMASK_ADDRESS)
			// `msgSender == from || msgSender == approvedAddress`.
			result := or(eq(msgSender, from), eq(msgSender, approvedAddress))
		}
	}

	/**
	 * @dev Transfers `tokenId` from `from` to `to`.
	 *
	 * Requirements:
	 *
	 * - `to` cannot be the zero address.
	 * - `tokenId` token must be owned by `from`.
	 *
	 * Emits a {Transfer} event.
	 */
	function 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) = _getApprovedAddress(tokenId);

		// The nested ifs save around 20+ gas over a compound boolean condition.
		if (!_isOwnerOrApproved(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 `_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) = _getApprovedAddress(tokenId);

		if (approvalCheck) {
			// The nested ifs save around 20+ gas over a compound boolean condition.
			if (!_isOwnerOrApproved(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++;
		}
	}

	/**
	 * @dev Internal function to invoke {IERC721Receiver-onERC721Received} on a target contract.
	 *
	 * @param from address representing the previous owner of the given token ID
	 * @param to target address that will receive the tokens
	 * @param tokenId uint256 ID of the token to be transferred
	 * @param _data bytes optional data to send along with the call
	 * @return bool whether the call correctly returned the expected magic value
	 */
	function _checkContractOnERC721Received(
		address from,
		address to,
		uint256 tokenId,
		bytes memory _data
	) private returns (bool) {
		try
			ERC721A__IERC721Receiver(to).onERC721Received(_msgSenderERC721A(), from, tokenId, _data)
		returns (bytes4 retval) {
			return retval == ERC721A__IERC721Receiver(to).onERC721Received.selector;
		} catch (bytes memory reason) {
			if (reason.length == 0) {
				revert TransferToNonERC721ReceiverImplementer();
			} else {
				assembly {
					revert(add(32, reason), mload(reason))
				}
			}
		}
	}

	/**
	 * @dev Directly sets the extra data for the ownership data `index`.
	 */
	function _setExtraDataAt(uint256 index, uint24 extraData) internal {
		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 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;
	}

	/**
	 * @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 Hook that is called before a set of serially-ordered token ids are about to be transferred.
	 * This includes minting.
	 * And also called before burning one token.
	 *
	 * startTokenId - the first token id to be transferred
	 * quantity - the amount to be transferred
	 *
	 * Calling conditions:
	 *
	 * - When `from` and `to` are both non-zero, `from`'s `tokenId` will be
	 * transferred to `to`.
	 * - When `from` is zero, `tokenId` will be minted for `to`.
	 * - When `to` is zero, `tokenId` will be burned by `from`.
	 * - `from` and `to` are never both zero.
	 */
	function _beforeTokenTransfers(
		address from,
		address to,
		uint256 startTokenId,
		uint256 quantity
	) internal virtual {}

	/**
	 * @dev Hook that is called after a set of serially-ordered token ids have been transferred.
	 * This includes minting.
	 * And also called after one token has been burned.
	 *
	 * startTokenId - the first token id to be transferred
	 * quantity - the amount to be transferred
	 *
	 * Calling conditions:
	 *
	 * - When `from` and `to` are both non-zero, `from`'s `tokenId` has been
	 * transferred to `to`.
	 * - When `from` is zero, `tokenId` has been minted for `to`.
	 * - When `to` is zero, `tokenId` has been burned by `from`.
	 * - `from` and `to` are never both zero.
	 */
	function _afterTokenTransfers(
		address from,
		address to,
		uint256 startTokenId,
		uint256 quantity
	) internal virtual {}

	/**
	 * @dev Returns the message sender (defaults to `msg.sender`).
	 *
	 * If you are writing GSN compatible contracts, you need to override this function.
	 */
	function _msgSenderERC721A() internal view virtual returns (address) {
		return msg.sender;
	}

	/**
	 * @dev Converts a `uint256` to its ASCII `string` decimal representation.
	 */
	function _toString(uint256 value) internal pure returns (string memory ptr) {
		assembly {
			// The maximum value of a uint256 contains 78 digits (1 byte per digit),
			// but we allocate 128 bytes to keep the free memory pointer 32-byte word aliged.
			// We will need 1 32-byte word to store the length,
			// and 3 32-byte words to store a maximum of 78 digits. Total: 32 + 3 * 32 = 128.
			ptr := add(mload(0x40), 128)
			// Update the free memory pointer to allocate.
			mstore(0x40, ptr)

			// Cache the end of the memory to calculate the length later.
			let end := ptr

			// We write the string from the rightmost digit to the leftmost digit.
			// The following is essentially a do-while loop that also handles the zero case.
			// Costs a bit more than early returning for the zero case,
			// but cheaper in terms of deployment and overall runtime costs.
			for {
				// Initialize and perform the first pass without check.
				let temp := value
				// Move the pointer 1 byte leftwards to point to an empty character slot.
				ptr := sub(ptr, 1)
				// Write the character to the pointer. 48 is the ASCII index of '0'.
				mstore8(ptr, add(48, mod(temp, 10)))
				temp := div(temp, 10)
			} temp {
				// Keep dividing `temp` until zero.
				temp := div(temp, 10)
			} {
				// Body of the for loop.
				ptr := sub(ptr, 1)
				mstore8(ptr, add(48, mod(temp, 10)))
			}

			let length := sub(end, ptr)
			// Move the pointer 32 bytes leftwards to make room for the length.
			ptr := sub(ptr, 32)
			// Store the length.
			mstore(ptr, length)
		}
	}
}