// File: contracts/Token.sol



// SPDX-License-Identifier: MIT
pragma solidity ^0.8.4;

import "@openzeppelin/contracts/token/ERC721/ERC721.sol";
import "@openzeppelin/contracts/token/ERC721/extensions/ERC721Enumerable.sol";
import "@openzeppelin/contracts/access/Ownable.sol";
import "@openzeppelin/contracts/utils/Counters.sol";
import "@openzeppelin/contracts/utils/math/SafeMath.sol";

import "./Util.sol";
import "./Mouth.sol";
import "./Eyes.sol";
import "./Nose.sol";

contract Token is ERC721, ERC721Enumerable, Ownable {
    using Counters for Counters.Counter;
    using SafeMath for uint256;

    Counters.Counter private _tokenIdCounter;
    uint256 private constant maxTokensPerTransaction = 10;
    uint256 private tokenPrice = 0.05 ether;
    uint256 private constant tokenMaxSupply = 303;

    address private _a = 0x919036152224102F223641057770F8895a12c46C;
    address private _b = 0xF9466BE8B026ee4Fe22B69e69D84e95f515320e6;
    address private _c = 0x000001947A9A22D0C77097FF1942E7Cf9385C1Ba;

    ERC721 public banana = ERC721(0xa6DE47a17f35dbDC4f6806De0f538e0a7b744Ea6);

    mapping(address => bool) private activate_address;

    mapping(uint256 => uint256) private _seeds;

    constructor() ERC721("OnChain Halloween", "JOL") {}

    function _beforeTokenTransfer(
        address from,
        address to,
        uint256 tokenId
    ) internal override(ERC721, ERC721Enumerable) {
        super._beforeTokenTransfer(from, to, tokenId);
    }

    function getPrice() public view returns (uint256) {
        return tokenPrice;
    }

    function getDiscount(address user) public view returns (uint256) {
        uint256 discount = 0;
        if (!activate_address[user]) {
            discount = banana.balanceOf(user).mul(tokenPrice);
        }
        return discount;
    }

    function getTotalPrice(uint256 tokensNumber) public view returns (uint256) {
        uint256 discont = getDiscount(msg.sender);
        uint256 price = 0;
        if (tokenPrice.mul(tokensNumber) > discont) {
            price = tokenPrice.mul(tokensNumber).sub(discont);
        }
        return price;
    }

    function getSeed(uint256 tokenId) public view returns (uint256) {
        require(
            tokenId < _tokenIdCounter.current(),
            "call to a non-exisitent token"
        );
        return _seeds[tokenId];
    }

    function supportsInterface(bytes4 interfaceId)
        public
        view
        override(ERC721, ERC721Enumerable)
        returns (bool)
    {
        return super.supportsInterface(interfaceId);
    }

    function _envelop(string[8] memory params)
        private
        pure
        returns (string memory)
    {
        string[11] memory template;
        template[
            0
        ] = '<?xml version="1.0" encoding="utf-8"?><svg width="800" height="800" xmlns="http://www.w3.org/2000/svg" fill="#000"><defs><radialGradient id="rg1" r="300" gradientUnits="userSpaceOnUse"><stop stop-color="';
        template[1] = '" offset="0"/><stop stop-color="';
        template[
            2
        ] = '" stop-opacity="0" offset=".8"/></radialGradient><filter id="fl1"><feMorphology result="fr1" radius="25" in="SourceGraphic"/><feGaussianBlur stdDeviation="3" in="fr1" result="fr2"/><feOffset dy="30" in="fr2" result="fr3"/><feBlend mode="lighten" in2="fr3" in="SourceGraphic" result="fr5"/><feTurbulence result="fr4" in="SourceGraphic" baseFrequency=".02" numOctaves="1" type="fractalNoise"><animate attributeName="seed" values="1;2;3;4;5;6;7;8;9" dur="1" repeatCount="indefinite"/></feTurbulence><feDisplacementMap in2="fr4" in="fr5" scale="60" yChannelSelector="G"/></filter><radialGradient id="rg4" gradientUnits="userSpaceOnUse"><stop offset="0" stop-color="';
        template[3] = '"/><stop stop-color="';
        template[
            4
        ] = '"><animate attributeName="offset" values=".8;1" dur=".2" repeatCount="indefinite"/></stop></radialGradient><radialGradient id="rg5" gradientUnits="userSpaceOnUse"><stop offset="0" stop-color="';
        template[
            5
        ] = '"/><stop stop-color="#000"><animate attributeName="offset" values=".9;1" dur=".3" repeatCount="indefinite"/></stop></radialGradient><path id="bd" d="M0,0H800V800H-800Z"/><path id="mo" d="';
        template[6] = '"/><path id="le" d="';
        template[7] = '"/><path id="re" d="';
        template[8] = '"/><path id="ns" d="';
        template[
            9
        ] = '"/><g id="mb"><use href="#bd" fill="#FFF"/><use href="#mo"/><use href="#le"/><use href="#ns"/><use href="#re"/></g><g id="mbs"><use href="#bd" fill="#FFF"/><use href="#mo" transform="translate(0,-20)"/><use href="#ns" /><use href="#le" transform="translate(20,0)"/><use href="#re" transform="translate(-20,0)"/></g><mask id="m1"><use href="#mb"/></mask><mask id="m2"><use href="#mbs"/></mask></defs><use href="#bd" fill="url(#rg5)"/><path fill="url(#rg1)" filter="url(#fl1)" d="M400,350c-55,180-85,170-75,240c10,65,140,70,150,0c10-80-25-65-75-240"/><use href="#bd" mask="url(#m2)" fill="url(#rg4)"/><use href="#bd" mask="url(#m1)" fill="#000"/><circle cx="400" cy="400" r="400" fill="url(#rg5)" opacity=".2"/></svg>';
        string memory output1 = string(
            abi.encodePacked(
                template[0],
                params[0],
                template[1],
                params[1],
                template[2],
                params[0],
                template[3],
                params[1]
            )
        );
        string memory output2 = string(
            abi.encodePacked(
                template[4],
                params[2],
                template[5],
                params[3],
                template[6],
                params[4],
                template[7],
                params[5]
            )
        );
        string memory output3 = string(
            abi.encodePacked(template[8], params[6], template[9])
        );
        string memory output = string(
            abi.encodePacked(output1, output2, output3)
        );
        return output;
    }

    function _getColor(uint256 seeds)
        private
        pure
        returns (string[3] memory, uint256)
    {
        uint256 seed = seeds % 20;
        if (seed == 0) return (["#FF0", "#F00", "#93f"], seed);
        if (seed == 1) return (["#6F0", "#060", "#909"], seed);
        if (seed == 2) return (["#80C", "#C04", "#0ac"], seed);
        if (seed == 3) return (["#099", "#009", "#F90"], seed);
        if (seed == 4) return (["#FF0", "#F00", "#060"], seed);
        if (seed == 5) return (["#6F0", "#060", "#060"], seed);
        if (seed == 6) return (["#80C", "#C04", "#804"], seed);
        if (seed == 7) return (["#099", "#009", "#0CC"], seed);
        if (seed == 8) return (["#F00", "#FC0", "#9F0"], seed);
        if (seed == 9) return (["#F00", "#F0F", "#FF0"], seed);
        return (["#FF0", "#F60", "#900"], 10);
    }

    function _getSVG(uint256[4] memory traits)
        private
        pure
        returns (string memory, uint256[] memory)
    {
        uint256[] memory attr = new uint256[](3);
        string memory mouth;
        string[3] memory colors;
        (colors, attr[0]) = _getColor(traits[0]);
        string[2] memory eyes;
        (eyes, attr[1]) = _getEyes(traits[2]);
        (mouth, attr[2]) = _getMouth(traits[1]);
        string[8] memory params;
        params[0] = colors[0];
        params[1] = colors[1];
        params[2] = colors[2];
        params[3] = mouth;
        params[4] = eyes[0];
        params[5] = eyes[1];
        params[6] = _getNose(traits[3]);
        return (_envelop(params), attr);
    }

    function _getAttributes(uint256[] memory attr)
        private
        pure
        returns (string memory)
    {
        string memory output = string(
            abi.encodePacked(
                '[{ "trait_type": "Color", "value": "',
                Util.toStr(attr[0]),
                '"},{ "trait_type": "Eyes", "value": "',
                Util.toStr(attr[1]),
                '"},{ "trait_type": "Mouth", "value": "',
                Util.toStr(attr[2]),
                '"}]'
            )
        );
        return output;
    }

    function tokenURI(uint256 tokenId)
        public
        view
        override(ERC721)
        returns (string memory)
    {
        require(
            tokenId < _tokenIdCounter.current(),
            "call to a non-exisitent token"
        );

        uint256 seed = _seeds[tokenId];
        uint256[4] memory traits;
        traits[0] = seed % 1000;
        traits[1] = (seed /= 1000) % 1000;
        traits[2] = (seed /= 1000) % 1000;
        traits[3] = (seed /= 1000) % 1000;

        string memory output;
        uint256[] memory attr;

        (output, attr) = _getSVG(traits);

        string memory attributes = _getAttributes(attr);

        string memory json = Base64.encode(
            bytes(
                string(
                    abi.encodePacked(
                        '{"name": "OnChain Halloween #',
                        Util.toStr(tokenId),
                        '", "description": "Happy OnChain Halloween!  ","attributes":',
                        attributes,
                        ', "image": "data:image/svg+xml;base64,',
                        Base64.encode(bytes(output)),
                        '"}'
                    )
                )
            )
        );

        output = string(
            abi.encodePacked("data:application/json;base64,", json)
        );

        return output;
    }

    function withdraw() external onlyOwner {
        uint256 balance = address(this).balance;
        uint256 split = balance.div(3);
        require(payable(_a).send(split), "Failed to transfer funds to A");
        require(payable(_b).send(split), "Failed to transfer funds to B");
        require(payable(_c).send(split), "Failed to transfer funds to C");
    }

    function buy(uint256 tokensNumber) public payable {
        require(tokensNumber > 0, "the number is too small");
        require(
            tokensNumber <= maxTokensPerTransaction,
            "number of tokens exceeds the range"
        );
        require(
            _tokenIdCounter.current().add(tokensNumber) <= tokenMaxSupply,
            "number of tokens exceeds the range"
        );
        require(
            getTotalPrice(tokensNumber) <= msg.value,
            "The amount is not enough"
        );
        uint256 price = getTotalPrice(tokensNumber);

        if (msg.value > price) {
            uint256 repayBalance = msg.value.sub(price);
            payable(msg.sender).transfer(repayBalance);
        }

        for (uint256 i = 0; i < tokensNumber; i++) {
            uint256 seed = uint256(
                keccak256(
                    abi.encodePacked(
                        uint256(uint160(msg.sender)),
                        uint256(blockhash(block.number - 1)),
                        _tokenIdCounter.current(),
                        "hid8"
                    )
                )
            );
            _seeds[_tokenIdCounter.current()] = seed;
            _safeMint(msg.sender, _tokenIdCounter.current());
            _tokenIdCounter.increment();
        }

        activate_address[msg.sender] = true;
    }

    function buyOwner(uint256 tokensNumber) public onlyOwner {
        require(tokensNumber > 0, "the number is too small");
        require(
            tokensNumber <= maxTokensPerTransaction,
            "number of tokens exceeds the range"
        );
        require(
            _tokenIdCounter.current().add(tokensNumber) <= tokenMaxSupply,
            "number of tokens exceeds the range"
        );

        for (uint256 i = 0; i < tokensNumber; i++) {
            uint256 seed = uint256(
                keccak256(
                    abi.encodePacked(
                        uint256(uint160(msg.sender)),
                        uint256(blockhash(block.number - 1)),
                        _tokenIdCounter.current(),
                        "hid8"
                    )
                )
            );
            _seeds[_tokenIdCounter.current()] = seed;
            _safeMint(msg.sender, _tokenIdCounter.current());
            _tokenIdCounter.increment();
        }
    }
}

library Base64 {
    bytes internal constant TABLE =
        "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/";

    function encode(bytes memory data) internal pure returns (string memory) {
        uint256 len = data.length;
        if (len == 0) return "";
        uint256 encodedLen = 4 * ((len + 2) / 3);
        bytes memory result = new bytes(encodedLen + 32);
        bytes memory table = TABLE;
        assembly {
            let tablePtr := add(table, 1)
            let resultPtr := add(result, 32)
            for {
                let i := 0
            } lt(i, len) {

            } {
                i := add(i, 3)
                let input := and(mload(add(data, i)), 0xffffff)
                let out := mload(add(tablePtr, and(shr(18, input), 0x3F)))
                out := shl(8, out)
                out := add(
                    out,
                    and(mload(add(tablePtr, and(shr(12, input), 0x3F))), 0xFF)
                )
                out := shl(8, out)
                out := add(
                    out,
                    and(mload(add(tablePtr, and(shr(6, input), 0x3F))), 0xFF)
                )
                out := shl(8, out)
                out := add(
                    out,
                    and(mload(add(tablePtr, and(input, 0x3F))), 0xFF)
                )
                out := shl(224, out)
                mstore(resultPtr, out)
                resultPtr := add(resultPtr, 4)
            }
            switch mod(len, 3)
            case 1 {
                mstore(sub(resultPtr, 2), shl(240, 0x3d3d))
            }
            case 2 {
                mstore(sub(resultPtr, 1), shl(248, 0x3d))
            }
            mstore(result, encodedLen)
        }
        return string(result);
    }
}

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



// SPDX-License-Identifier: MIT

pragma solidity ^0.8.0;

import "./IERC721.sol";
import "./IERC721Receiver.sol";
import "./extensions/IERC721Metadata.sol";
import "../../utils/Address.sol";
import "../../utils/Context.sol";
import "../../utils/Strings.sol";
import "../../utils/introspection/ERC165.sol";

/**
 * @dev Implementation of https://eips.ethereum.org/EIPS/eip-721[ERC721] Non-Fungible Token Standard, including
 * the Metadata extension, but not including the Enumerable extension, which is available separately as
 * {ERC721Enumerable}.
 */
contract ERC721 is Context, ERC165, IERC721, IERC721Metadata {
    using Address for address;
    using Strings for uint256;

    // Token name
    string private _name;

    // Token symbol
    string private _symbol;

    // Mapping from token ID to owner address
    mapping(uint256 => address) private _owners;

    // Mapping owner address to token count
    mapping(address => uint256) private _balances;

    // 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;

    /**
     * @dev Initializes the contract by setting a `name` and a `symbol` to the token collection.
     */
    constructor(string memory name_, string memory symbol_) {
        _name = name_;
        _symbol = symbol_;
    }

    /**
     * @dev See {IERC165-supportsInterface}.
     */
    function supportsInterface(bytes4 interfaceId) public view virtual override(ERC165, IERC165) returns (bool) {
        return
            interfaceId == type(IERC721).interfaceId ||
            interfaceId == type(IERC721Metadata).interfaceId ||
            super.supportsInterface(interfaceId);
    }

    /**
     * @dev See {IERC721-balanceOf}.
     */
    function balanceOf(address owner) public view virtual override returns (uint256) {
        require(owner != address(0), "ERC721: balance query for the zero address");
        return _balances[owner];
    }

    /**
     * @dev See {IERC721-ownerOf}.
     */
    function ownerOf(uint256 tokenId) public view virtual override returns (address) {
        address owner = _owners[tokenId];
        require(owner != address(0), "ERC721: owner query for nonexistent token");
        return owner;
    }

    /**
     * @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) {
        require(_exists(tokenId), "ERC721Metadata: URI query for nonexistent token");

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

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

    /**
     * @dev See {IERC721-approve}.
     */
    function approve(address to, uint256 tokenId) public virtual override {
        address owner = ERC721.ownerOf(tokenId);
        require(to != owner, "ERC721: approval to current owner");

        require(
            _msgSender() == owner || isApprovedForAll(owner, _msgSender()),
            "ERC721: approve caller is not owner nor approved for all"
        );

        _approve(to, tokenId);
    }

    /**
     * @dev See {IERC721-getApproved}.
     */
    function getApproved(uint256 tokenId) public view virtual override returns (address) {
        require(_exists(tokenId), "ERC721: approved query for nonexistent token");

        return _tokenApprovals[tokenId];
    }

    /**
     * @dev See {IERC721-setApprovalForAll}.
     */
    function setApprovalForAll(address operator, bool approved) public virtual override {
        require(operator != _msgSender(), "ERC721: approve to caller");

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

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

    /**
     * @dev See {IERC721-transferFrom}.
     */
    function transferFrom(
        address from,
        address to,
        uint256 tokenId
    ) public virtual override {
        //solhint-disable-next-line max-line-length
        require(_isApprovedOrOwner(_msgSender(), tokenId), "ERC721: transfer caller is not owner nor approved");

        _transfer(from, to, tokenId);
    }

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

    /**
     * @dev See {IERC721-safeTransferFrom}.
     */
    function safeTransferFrom(
        address from,
        address to,
        uint256 tokenId,
        bytes memory _data
    ) public virtual override {
        require(_isApprovedOrOwner(_msgSender(), tokenId), "ERC721: transfer caller is not owner nor approved");
        _safeTransfer(from, to, tokenId, _data);
    }

    /**
     * @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.
     *
     * `_data` is additional data, it has no specified format and it is sent in call to `to`.
     *
     * This internal function is equivalent to {safeTransferFrom}, and can be used to e.g.
     * implement alternative mechanisms to perform token transfer, such as signature-based.
     *
     * Requirements:
     *
     * - `from` cannot be the zero address.
     * - `to` cannot be the zero address.
     * - `tokenId` token must exist and be owned by `from`.
     * - If `to` refers to a smart contract, it must implement {IERC721Receiver-onERC721Received}, which is called upon a safe transfer.
     *
     * Emits a {Transfer} event.
     */
    function _safeTransfer(
        address from,
        address to,
        uint256 tokenId,
        bytes memory _data
    ) internal virtual {
        _transfer(from, to, tokenId);
        require(_checkOnERC721Received(from, to, tokenId, _data), "ERC721: transfer to non ERC721Receiver implementer");
    }

    /**
     * @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`),
     * and stop existing when they are burned (`_burn`).
     */
    function _exists(uint256 tokenId) internal view virtual returns (bool) {
        return _owners[tokenId] != address(0);
    }

    /**
     * @dev Returns whether `spender` is allowed to manage `tokenId`.
     *
     * Requirements:
     *
     * - `tokenId` must exist.
     */
    function _isApprovedOrOwner(address spender, uint256 tokenId) internal view virtual returns (bool) {
        require(_exists(tokenId), "ERC721: operator query for nonexistent token");
        address owner = ERC721.ownerOf(tokenId);
        return (spender == owner || getApproved(tokenId) == spender || isApprovedForAll(owner, spender));
    }

    /**
     * @dev Safely mints `tokenId` and transfers it to `to`.
     *
     * Requirements:
     *
     * - `tokenId` must not exist.
     * - If `to` refers to a smart contract, it must implement {IERC721Receiver-onERC721Received}, which is called upon a safe transfer.
     *
     * Emits a {Transfer} event.
     */
    function _safeMint(address to, uint256 tokenId) internal virtual {
        _safeMint(to, tokenId, "");
    }

    /**
     * @dev Same as {xref-ERC721-_safeMint-address-uint256-}[`_safeMint`], with an additional `data` parameter which is
     * forwarded in {IERC721Receiver-onERC721Received} to contract recipients.
     */
    function _safeMint(
        address to,
        uint256 tokenId,
        bytes memory _data
    ) internal virtual {
        _mint(to, tokenId);
        require(
            _checkOnERC721Received(address(0), to, tokenId, _data),
            "ERC721: transfer to non ERC721Receiver implementer"
        );
    }

    /**
     * @dev Mints `tokenId` and transfers it to `to`.
     *
     * WARNING: Usage of this method is discouraged, use {_safeMint} whenever possible
     *
     * Requirements:
     *
     * - `tokenId` must not exist.
     * - `to` cannot be the zero address.
     *
     * Emits a {Transfer} event.
     */
    function _mint(address to, uint256 tokenId) internal virtual {
        require(to != address(0), "ERC721: mint to the zero address");
        require(!_exists(tokenId), "ERC721: token already minted");

        _beforeTokenTransfer(address(0), to, tokenId);

        _balances[to] += 1;
        _owners[tokenId] = to;

        emit Transfer(address(0), to, tokenId);
    }

    /**
     * @dev Destroys `tokenId`.
     * The approval is cleared when the token is burned.
     *
     * Requirements:
     *
     * - `tokenId` must exist.
     *
     * Emits a {Transfer} event.
     */
    function _burn(uint256 tokenId) internal virtual {
        address owner = ERC721.ownerOf(tokenId);

        _beforeTokenTransfer(owner, address(0), tokenId);

        // Clear approvals
        _approve(address(0), tokenId);

        _balances[owner] -= 1;
        delete _owners[tokenId];

        emit Transfer(owner, address(0), tokenId);
    }

    /**
     * @dev Transfers `tokenId` from `from` to `to`.
     *  As opposed to {transferFrom}, this imposes no restrictions on msg.sender.
     *
     * Requirements:
     *
     * - `to` cannot be the zero address.
     * - `tokenId` token must be owned by `from`.
     *
     * Emits a {Transfer} event.
     */
    function _transfer(
        address from,
        address to,
        uint256 tokenId
    ) internal virtual {
        require(ERC721.ownerOf(tokenId) == from, "ERC721: transfer of token that is not own");
        require(to != address(0), "ERC721: transfer to the zero address");

        _beforeTokenTransfer(from, to, tokenId);

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

        _balances[from] -= 1;
        _balances[to] += 1;
        _owners[tokenId] = to;

        emit Transfer(from, to, tokenId);
    }

    /**
     * @dev Approve `to` to operate on `tokenId`
     *
     * Emits a {Approval} event.
     */
    function _approve(address to, uint256 tokenId) internal virtual {
        _tokenApprovals[tokenId] = to;
        emit Approval(ERC721.ownerOf(tokenId), to, tokenId);
    }

    /**
     * @dev Internal function to invoke {IERC721Receiver-onERC721Received} on a target address.
     * The call is not executed if the target address is not a 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 _checkOnERC721Received(
        address from,
        address to,
        uint256 tokenId,
        bytes memory _data
    ) private returns (bool) {
        if (to.isContract()) {
            try IERC721Receiver(to).onERC721Received(_msgSender(), from, tokenId, _data) returns (bytes4 retval) {
                return retval == IERC721Receiver.onERC721Received.selector;
            } catch (bytes memory reason) {
                if (reason.length == 0) {
                    revert("ERC721: transfer to non ERC721Receiver implementer");
                } else {
                    assembly {
                        revert(add(32, reason), mload(reason))
                    }
                }
            }
        } else {
            return true;
        }
    }

    /**
     * @dev Hook that is called before any token transfer. This includes minting
     * and burning.
     *
     * 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, ``from``'s `tokenId` will be burned.
     * - `from` and `to` are never both zero.
     *
     * To learn more about hooks, head to xref:ROOT:extending-contracts.adoc#using-hooks[Using Hooks].
     */
    function _beforeTokenTransfer(
        address from,
        address to,
        uint256 tokenId
    ) internal virtual {}
}

// File: @openzeppelin/contracts/token/ERC721/extensions/ERC721Enumerable.sol



// SPDX-License-Identifier: MIT

pragma solidity ^0.8.0;

import "../ERC721.sol";
import "./IERC721Enumerable.sol";

/**
 * @dev This implements an optional extension of {ERC721} defined in the EIP that adds
 * enumerability of all the token ids in the contract as well as all token ids owned by each
 * account.
 */
abstract contract ERC721Enumerable is ERC721, IERC721Enumerable {
    // Mapping from owner to list of owned token IDs
    mapping(address => mapping(uint256 => uint256)) private _ownedTokens;

    // Mapping from token ID to index of the owner tokens list
    mapping(uint256 => uint256) private _ownedTokensIndex;

    // Array with all token ids, used for enumeration
    uint256[] private _allTokens;

    // Mapping from token id to position in the allTokens array
    mapping(uint256 => uint256) private _allTokensIndex;

    /**
     * @dev See {IERC165-supportsInterface}.
     */
    function supportsInterface(bytes4 interfaceId) public view virtual override(IERC165, ERC721) returns (bool) {
        return interfaceId == type(IERC721Enumerable).interfaceId || super.supportsInterface(interfaceId);
    }

    /**
     * @dev See {IERC721Enumerable-tokenOfOwnerByIndex}.
     */
    function tokenOfOwnerByIndex(address owner, uint256 index) public view virtual override returns (uint256) {
        require(index < ERC721.balanceOf(owner), "ERC721Enumerable: owner index out of bounds");
        return _ownedTokens[owner][index];
    }

    /**
     * @dev See {IERC721Enumerable-totalSupply}.
     */
    function totalSupply() public view virtual override returns (uint256) {
        return _allTokens.length;
    }

    /**
     * @dev See {IERC721Enumerable-tokenByIndex}.
     */
    function tokenByIndex(uint256 index) public view virtual override returns (uint256) {
        require(index < ERC721Enumerable.totalSupply(), "ERC721Enumerable: global index out of bounds");
        return _allTokens[index];
    }

    /**
     * @dev Hook that is called before any token transfer. This includes minting
     * and burning.
     *
     * 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, ``from``'s `tokenId` will be burned.
     * - `from` cannot be the zero address.
     * - `to` cannot be the zero address.
     *
     * To learn more about hooks, head to xref:ROOT:extending-contracts.adoc#using-hooks[Using Hooks].
     */
    function _beforeTokenTransfer(
        address from,
        address to,
        uint256 tokenId
    ) internal virtual override {
        super._beforeTokenTransfer(from, to, tokenId);

        if (from == address(0)) {
            _addTokenToAllTokensEnumeration(tokenId);
        } else if (from != to) {
            _removeTokenFromOwnerEnumeration(from, tokenId);
        }
        if (to == address(0)) {
            _removeTokenFromAllTokensEnumeration(tokenId);
        } else if (to != from) {
            _addTokenToOwnerEnumeration(to, tokenId);
        }
    }

    /**
     * @dev Private function to add a token to this extension's ownership-tracking data structures.
     * @param to address representing the new owner of the given token ID
     * @param tokenId uint256 ID of the token to be added to the tokens list of the given address
     */
    function _addTokenToOwnerEnumeration(address to, uint256 tokenId) private {
        uint256 length = ERC721.balanceOf(to);
        _ownedTokens[to][length] = tokenId;
        _ownedTokensIndex[tokenId] = length;
    }

    /**
     * @dev Private function to add a token to this extension's token tracking data structures.
     * @param tokenId uint256 ID of the token to be added to the tokens list
     */
    function _addTokenToAllTokensEnumeration(uint256 tokenId) private {
        _allTokensIndex[tokenId] = _allTokens.length;
        _allTokens.push(tokenId);
    }

    /**
     * @dev Private function to remove a token from this extension's ownership-tracking data structures. Note that
     * while the token is not assigned a new owner, the `_ownedTokensIndex` mapping is _not_ updated: this allows for
     * gas optimizations e.g. when performing a transfer operation (avoiding double writes).
     * This has O(1) time complexity, but alters the order of the _ownedTokens array.
     * @param from address representing the previous owner of the given token ID
     * @param tokenId uint256 ID of the token to be removed from the tokens list of the given address
     */
    function _removeTokenFromOwnerEnumeration(address from, uint256 tokenId) private {
        // To prevent a gap in from's tokens array, we store the last token in the index of the token to delete, and
        // then delete the last slot (swap and pop).

        uint256 lastTokenIndex = ERC721.balanceOf(from) - 1;
        uint256 tokenIndex = _ownedTokensIndex[tokenId];

        // When the token to delete is the last token, the swap operation is unnecessary
        if (tokenIndex != lastTokenIndex) {
            uint256 lastTokenId = _ownedTokens[from][lastTokenIndex];

            _ownedTokens[from][tokenIndex] = lastTokenId; // Move the last token to the slot of the to-delete token
            _ownedTokensIndex[lastTokenId] = tokenIndex; // Update the moved token's index
        }

        // This also deletes the contents at the last position of the array
        delete _ownedTokensIndex[tokenId];
        delete _ownedTokens[from][lastTokenIndex];
    }

    /**
     * @dev Private function to remove a token from this extension's token tracking data structures.
     * This has O(1) time complexity, but alters the order of the _allTokens array.
     * @param tokenId uint256 ID of the token to be removed from the tokens list
     */
    function _removeTokenFromAllTokensEnumeration(uint256 tokenId) private {
        // To prevent a gap in the tokens array, we store the last token in the index of the token to delete, and
        // then delete the last slot (swap and pop).

        uint256 lastTokenIndex = _allTokens.length - 1;
        uint256 tokenIndex = _allTokensIndex[tokenId];

        // When the token to delete is the last token, the swap operation is unnecessary. However, since this occurs so
        // rarely (when the last minted token is burnt) that we still do the swap here to avoid the gas cost of adding
        // an 'if' statement (like in _removeTokenFromOwnerEnumeration)
        uint256 lastTokenId = _allTokens[lastTokenIndex];

        _allTokens[tokenIndex] = lastTokenId; // Move the last token to the slot of the to-delete token
        _allTokensIndex[lastTokenId] = tokenIndex; // Update the moved token's index

        // This also deletes the contents at the last position of the array
        delete _allTokensIndex[tokenId];
        _allTokens.pop();
    }
}

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



// SPDX-License-Identifier: MIT

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() {
        _setOwner(_msgSender());
    }

    /**
     * @dev Returns the address of the current owner.
     */
    function owner() public view virtual returns (address) {
        return _owner;
    }

    /**
     * @dev Throws if called by any account other than the owner.
     */
    modifier onlyOwner() {
        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 {
        _setOwner(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");
        _setOwner(newOwner);
    }

    function _setOwner(address newOwner) private {
        address oldOwner = _owner;
        _owner = newOwner;
        emit OwnershipTransferred(oldOwner, newOwner);
    }
}

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



// SPDX-License-Identifier: MIT

pragma solidity ^0.8.0;

/**
 * @title Counters
 * @author Matt Condon (@shrugs)
 * @dev Provides counters that can only be incremented, decremented or reset. This can be used e.g. to track the number
 * of elements in a mapping, issuing ERC721 ids, or counting request ids.
 *
 * Include with `using Counters for Counters.Counter;`
 */
library Counters {
    struct Counter {
        // This variable should never be directly accessed by users of the library: interactions must be restricted to
        // the library's function. As of Solidity v0.5.2, this cannot be enforced, though there is a proposal to add
        // this feature: see https://github.com/ethereum/solidity/issues/4637
        uint256 _value; // default: 0
    }

    function current(Counter storage counter) internal view returns (uint256) {
        return counter._value;
    }

    function increment(Counter storage counter) internal {
        unchecked {
            counter._value += 1;
        }
    }

    function decrement(Counter storage counter) internal {
        uint256 value = counter._value;
        require(value > 0, "Counter: decrement overflow");
        unchecked {
            counter._value = value - 1;
        }
    }

    function reset(Counter storage counter) internal {
        counter._value = 0;
    }
}

// File: @openzeppelin/contracts/utils/math/SafeMath.sol



// SPDX-License-Identifier: MIT

pragma solidity ^0.8.0;

// CAUTION
// This version of SafeMath should only be used with Solidity 0.8 or later,
// because it relies on the compiler's built in overflow checks.

/**
 * @dev Wrappers over Solidity's arithmetic operations.
 *
 * NOTE: `SafeMath` is no longer needed starting with Solidity 0.8. The compiler
 * now has built in overflow checking.
 */
library SafeMath {
    /**
     * @dev Returns the addition of two unsigned integers, with an overflow flag.
     *
     * _Available since v3.4._
     */
    function tryAdd(uint256 a, uint256 b) internal pure returns (bool, uint256) {
        unchecked {
            uint256 c = a + b;
            if (c < a) return (false, 0);
            return (true, c);
        }
    }

    /**
     * @dev Returns the substraction of two unsigned integers, with an overflow flag.
     *
     * _Available since v3.4._
     */
    function trySub(uint256 a, uint256 b) internal pure returns (bool, uint256) {
        unchecked {
            if (b > a) return (false, 0);
            return (true, a - b);
        }
    }

    /**
     * @dev Returns the multiplication of two unsigned integers, with an overflow flag.
     *
     * _Available since v3.4._
     */
    function tryMul(uint256 a, uint256 b) internal pure returns (bool, uint256) {
        unchecked {
            // Gas optimization: this is cheaper than requiring 'a' not being zero, but the
            // benefit is lost if 'b' is also tested.
            // See: https://github.com/OpenZeppelin/openzeppelin-contracts/pull/522
            if (a == 0) return (true, 0);
            uint256 c = a * b;
            if (c / a != b) return (false, 0);
            return (true, c);
        }
    }

    /**
     * @dev Returns the division of two unsigned integers, with a division by zero flag.
     *
     * _Available since v3.4._
     */
    function tryDiv(uint256 a, uint256 b) internal pure returns (bool, uint256) {
        unchecked {
            if (b == 0) return (false, 0);
            return (true, a / b);
        }
    }

    /**
     * @dev Returns the remainder of dividing two unsigned integers, with a division by zero flag.
     *
     * _Available since v3.4._
     */
    function tryMod(uint256 a, uint256 b) internal pure returns (bool, uint256) {
        unchecked {
            if (b == 0) return (false, 0);
            return (true, a % b);
        }
    }

    /**
     * @dev Returns the addition of two unsigned integers, reverting on
     * overflow.
     *
     * Counterpart to Solidity's `+` operator.
     *
     * Requirements:
     *
     * - Addition cannot overflow.
     */
    function add(uint256 a, uint256 b) internal pure returns (uint256) {
        return a + b;
    }

    /**
     * @dev Returns the subtraction of two unsigned integers, reverting on
     * overflow (when the result is negative).
     *
     * Counterpart to Solidity's `-` operator.
     *
     * Requirements:
     *
     * - Subtraction cannot overflow.
     */
    function sub(uint256 a, uint256 b) internal pure returns (uint256) {
        return a - b;
    }

    /**
     * @dev Returns the multiplication of two unsigned integers, reverting on
     * overflow.
     *
     * Counterpart to Solidity's `*` operator.
     *
     * Requirements:
     *
     * - Multiplication cannot overflow.
     */
    function mul(uint256 a, uint256 b) internal pure returns (uint256) {
        return a * b;
    }

    /**
     * @dev Returns the integer division of two unsigned integers, reverting on
     * division by zero. The result is rounded towards zero.
     *
     * Counterpart to Solidity's `/` operator.
     *
     * Requirements:
     *
     * - The divisor cannot be zero.
     */
    function div(uint256 a, uint256 b) internal pure returns (uint256) {
        return a / b;
    }

    /**
     * @dev Returns the remainder of dividing two unsigned integers. (unsigned integer modulo),
     * reverting when dividing by zero.
     *
     * Counterpart to Solidity's `%` operator. This function uses a `revert`
     * opcode (which leaves remaining gas untouched) while Solidity uses an
     * invalid opcode to revert (consuming all remaining gas).
     *
     * Requirements:
     *
     * - The divisor cannot be zero.
     */
    function mod(uint256 a, uint256 b) internal pure returns (uint256) {
        return a % b;
    }

    /**
     * @dev Returns the subtraction of two unsigned integers, reverting with custom message on
     * overflow (when the result is negative).
     *
     * CAUTION: This function is deprecated because it requires allocating memory for the error
     * message unnecessarily. For custom revert reasons use {trySub}.
     *
     * Counterpart to Solidity's `-` operator.
     *
     * Requirements:
     *
     * - Subtraction cannot overflow.
     */
    function sub(
        uint256 a,
        uint256 b,
        string memory errorMessage
    ) internal pure returns (uint256) {
        unchecked {
            require(b <= a, errorMessage);
            return a - b;
        }
    }

    /**
     * @dev Returns the integer division of two unsigned integers, reverting with custom message on
     * division by zero. The result is rounded towards zero.
     *
     * Counterpart to Solidity's `/` operator. Note: this function uses a
     * `revert` opcode (which leaves remaining gas untouched) while Solidity
     * uses an invalid opcode to revert (consuming all remaining gas).
     *
     * Requirements:
     *
     * - The divisor cannot be zero.
     */
    function div(
        uint256 a,
        uint256 b,
        string memory errorMessage
    ) internal pure returns (uint256) {
        unchecked {
            require(b > 0, errorMessage);
            return a / b;
        }
    }

    /**
     * @dev Returns the remainder of dividing two unsigned integers. (unsigned integer modulo),
     * reverting with custom message when dividing by zero.
     *
     * CAUTION: This function is deprecated because it requires allocating memory for the error
     * message unnecessarily. For custom revert reasons use {tryMod}.
     *
     * Counterpart to Solidity's `%` operator. This function uses a `revert`
     * opcode (which leaves remaining gas untouched) while Solidity uses an
     * invalid opcode to revert (consuming all remaining gas).
     *
     * Requirements:
     *
     * - The divisor cannot be zero.
     */
    function mod(
        uint256 a,
        uint256 b,
        string memory errorMessage
    ) internal pure returns (uint256) {
        unchecked {
            require(b > 0, errorMessage);
            return a % b;
        }
    }
}

// File: contracts/Util.sol



// SPDX-License-Identifier: MIT
pragma solidity ^0.8.4;

library Util {
    function toStr(uint256 _i) internal pure returns (string memory) {
        if (_i == 0) return "0";
        uint256 j = _i;
        uint256 len;
        while (j != 0) {
            len++;
            j /= 10;
        }
        bytes memory buffer = new bytes(len);
        while (_i != 0) {
            len -= 1;
            buffer[len] = bytes1(uint8(48 + uint256(_i % 10)));
            _i /= 10;
        }
        return string(buffer);
    }

    function toFloatStr(uint256 x) internal pure returns (string memory) {
        if (x >= 100) return "1";
        if (x <= 0) return "0";
        return string(abi.encodePacked(".", toStr(x)));
    }
}

// File: contracts/Mouth.sol



// SPDX-License-Identifier: MIT
pragma solidity ^0.8.4;

import "./Util.sol";

function _getTTT(uint256 seed) pure returns (uint256[] memory) {
    uint256 idx = seed % 10;
    uint256[] memory tt;
    if (idx == 0) {
        tt = new uint256[](3);
        tt[0] = 0;
        tt[1] = 1;
        tt[2] = 1;
        return tt;
    }
    if (idx == 1) {
        tt = new uint256[](3);
        tt[0] = 1;
        tt[1] = 0;
        tt[2] = 1;
        return tt;
    }
    if (idx == 2) {
        tt = new uint256[](3);
        tt[0] = 1;
        tt[1] = 1;
        tt[2] = 0;
        return tt;
    }
    if (idx == 3) {
        tt = new uint256[](3);
        tt[0] = 1;
        tt[1] = 1;
        tt[2] = 1;
        return tt;
    }
    if (idx == 4) {
        tt = new uint256[](4);
        tt[0] = 0;
        tt[1] = 1;
        tt[2] = 0;
        tt[3] = 1;
        return tt;
    }
    if (idx == 5) {
        tt = new uint256[](4);
        tt[0] = 0;
        tt[1] = 1;
        tt[2] = 1;
        tt[3] = 0;
        return tt;
    }
    if (idx == 6) {
        tt = new uint256[](4);
        tt[0] = 1;
        tt[1] = 0;
        tt[2] = 0;
        tt[3] = 1;
        return tt;
    }
    if (idx == 7) {
        tt = new uint256[](4);
        tt[0] = 1;
        tt[1] = 0;
        tt[2] = 1;
        tt[3] = 0;
        return tt;
    }
    if (idx == 8) {
        tt = new uint256[](4);
        tt[0] = 1;
        tt[1] = 0;
        tt[2] = 1;
        tt[3] = 1;
        return tt;
    }
    tt = new uint256[](4);
    tt[0] = 1;
    tt[1] = 1;
    tt[2] = 0;
    tt[3] = 1;
    return tt;
}

function _getBTT(uint256 seed) pure returns (uint256[] memory) {
    uint256 idx = seed % 10;
    uint256[] memory tt;
    if (idx == 0) {
        tt = new uint256[](3);
        tt[0] = 0;
        tt[1] = 0;
        tt[2] = 1;
        return tt;
    }
    if (idx == 1) {
        tt = new uint256[](3);
        tt[0] = 0;
        tt[1] = 1;
        tt[2] = 0;
        return tt;
    }
    if (idx == 2) {
        tt = new uint256[](3);
        tt[0] = 1;
        tt[1] = 0;
        tt[2] = 0;
        return tt;
    }
    if (idx == 3) {
        tt = new uint256[](3);
        tt[0] = 0;
        tt[1] = 0;
        tt[2] = 0;
        return tt;
    }
    if (idx == 4) {
        tt = new uint256[](4);
        tt[0] = 0;
        tt[1] = 1;
        tt[2] = 0;
        tt[3] = 1;
        return tt;
    }
    if (idx == 5) {
        tt = new uint256[](4);
        tt[0] = 1;
        tt[1] = 0;
        tt[2] = 0;
        tt[3] = 1;
        return tt;
    }
    if (idx == 6) {
        tt = new uint256[](4);
        tt[0] = 0;
        tt[1] = 1;
        tt[2] = 1;
        tt[3] = 0;
        return tt;
    }
    if (idx == 7) {
        tt = new uint256[](4);
        tt[0] = 1;
        tt[1] = 0;
        tt[2] = 1;
        tt[3] = 0;
        return tt;
    }
    if (idx == 8) {
        tt = new uint256[](4);
        tt[0] = 0;
        tt[1] = 0;
        tt[2] = 1;
        tt[3] = 0;
        return tt;
    }
    tt = new uint256[](4);
    tt[0] = 0;
    tt[1] = 1;
    tt[2] = 0;
    tt[3] = 0;
    return tt;
}

function _getMouth_Sub(uint256[] memory ofst) pure returns (string memory) {
    string memory str = "";
    for (uint256 i = 0; i < ofst.length; i += 2) {
        str = string(
            abi.encodePacked(
                str,
                "L",
                Util.toStr(ofst[i]),
                ",",
                Util.toStr(ofst[i + 1])
            )
        );
    }
    return str;
}

function _getMouth(uint256 seeds) pure returns (string memory, uint256) {
    string memory tt = _getMouthT(seeds);
    string memory bt = _getMouthB(seeds);
    return (
        string(
            abi.encodePacked(
                "M115,470L175,490",
                tt,
                "L625,490L665,470L625,670",
                bt,
                "L175,670Z"
            )
        ),
        seeds % 10
    );
}

function _getMouthT(uint256 seeds) pure returns (string memory) {
    uint256[] memory tbl = _getTTT(seeds);
    uint256 freq = tbl.length;
    uint256 pw = 450 / freq;
    uint256 pm = pw / 6;
    uint256 pm3 = pm * 5;
    uint256 st = 175;
    uint256 num = 0;
    for (uint256 i = 0; i < tbl.length; i++) num += tbl[i];
    uint256[] memory ofst = new uint256[](num * 10);
    uint256 tc = 0;
    for (uint256 i = 0; i < tbl.length; i++) {
        uint256 t = st;
        if (tbl[i] == 1) {
            uint256 idb = tc * 10;
            ofst[idb + 0] = t + pm;
            ofst[idb + 1] = 490;
            ofst[idb + 2] = t + pm;
            ofst[idb + 3] = 540;
            ofst[idb + 4] = t + pm3;
            ofst[idb + 5] = 540;
            ofst[idb + 6] = t + pm3;
            ofst[idb + 7] = 490;
            ofst[idb + 8] = t + pw;
            ofst[idb + 9] = 490;
            tc++;
        }
        st = t + pw;
    }
    string memory ut = _getMouth_Sub(ofst);
    return ut;
}

function _getMouthB(uint256 seeds) pure returns (string memory) {
    uint256[] memory tbl = _getBTT(seeds);
    uint256 freq = tbl.length;
    uint256 pw = 450 / freq;
    uint256 pm = pw / 6;
    uint256 pm3 = pm * 5;
    uint256 st = 625;
    uint256 num = 0;
    for (uint256 i = 0; i < tbl.length; i++) num += tbl[i];
    uint256[] memory ofst = new uint256[](num * 10);
    uint256 tc = 0;
    for (uint256 i = 0; i < tbl.length; i++) {
        uint256 t = st;
        if (tbl[i] == 1) {
            uint256 idb = tc * 10;
            ofst[idb + 0] = t - pm;
            ofst[idb + 1] = 670;
            ofst[idb + 2] = t - pm;
            ofst[idb + 3] = 620;
            ofst[idb + 4] = t - pm3;
            ofst[idb + 5] = 620;
            ofst[idb + 6] = t - pm3;
            ofst[idb + 7] = 670;
            ofst[idb + 8] = t - pw;
            ofst[idb + 9] = 670;
            tc++;
        }
        st = t - pw;
    }
    string memory bt = _getMouth_Sub(ofst);
    return bt;
}

// File: contracts/Eyes.sol



// SPDX-License-Identifier: MIT
pragma solidity ^0.8.4;

import "./Util.sol";

function _getSPT(uint256 seed) pure returns (uint256[8] memory) {
    uint256 idx = seed % 6;
    if (idx == 0) return [uint256(0), 0, 1, 0, 0, 1, 0, 1];
    if (idx == 1) return [uint256(0), 1, 0, 0, 0, 1, 0, 1];
    if (idx == 2) return [uint256(1), 0, 1, 0, 0, 0, 1, 0];
    if (idx == 3) return [uint256(0), 1, 0, 1, 0, 0, 1, 0];
    if (idx == 4) return [uint256(1), 0, 0, 1, 0, 0, 1, 0];
    return [uint256(1), 0, 1, 0, 0, 1, 0, 0];
}

function _getPoint(
    bool clockwise,
    uint256 x,
    uint256 y,
    uint256 ofst
) pure returns (uint256[2] memory) {
    int256[8] memory tbl = [int256(1), 0, 0, 1, -1, 0, 0, -1];
    if (!clockwise) tbl = [int256(-1), 0, 0, 1, 1, 0, 0, -1];
    int256 mod = int256(ofst) % 250;
    uint256 div = ofst / 250;
    int256[2] memory p = [int256(x), int256(y)];
    uint256 i = 0;
    for (; i < div; i++) {
        p[0] += 250 * tbl[i * 2];
        p[1] += 250 * tbl[i * 2 + 1];
    }
    p[0] += mod * tbl[i * 2];
    p[1] += mod * tbl[i * 2 + 1];
    return [uint256(p[0]), uint256(p[1])];
}

function _getOffset(
    uint256[8] memory ptn,
    uint256 seeds,
    string memory salt
) pure returns (uint256[3] memory) {
    uint256 seed = uint256(keccak256(abi.encodePacked(salt, seeds)));
    uint256[3] memory rnd;
    seed /= 100;
    rnd[0] = seed % 100;
    seed /= 100;
    rnd[1] = seed % 100;
    seed /= 100;
    rnd[2] = seed % 100;
    uint256[3] memory ret;
    uint256 width = 125;
    uint256 idx = 0;
    for (uint256 i = 0; i < ptn.length; i++) {
        if (ptn[i] == 1) {
            ret[idx] = i * width + (rnd[idx] * 64) / 100 + 32;
            idx++;
        }
    }
    return ret;
}

function _reducer(uint256[] memory points) pure returns (string memory) {
    string memory ret = "";
    for (uint256 i = 0; i < points.length; i += 2) {
        ret = string(
            abi.encodePacked(
                ret,
                i == 0 ? "M" : "L",
                Util.toStr(points[i]),
                ",",
                Util.toStr(points[i + 1])
            )
        );
    }
    return string(abi.encodePacked(ret, "Z"));
}

function _getEyes(uint256 seeds) pure returns (string[2] memory, uint256) {
    uint256[8] memory ptn = _getSPT(seeds);
    uint256[3] memory ofs = _getOffset(ptn, seeds, "lefteye");
    uint256[] memory lep = new uint256[](6);
    for (uint256 i = 0; i < ofs.length; i++) {
        uint256[2] memory pt = _getPoint(true, 100, 180, ofs[i]);
        lep[i * 2] = pt[0];
        lep[i * 2 + 1] = pt[1];
    }
    ofs = _getOffset(ptn, seeds, "righteye");
    uint256[] memory rep = new uint256[](6);
    for (uint256 i = 0; i < ofs.length; i++) {
        uint256[2] memory pt = _getPoint(false, 700, 180, ofs[i]);
        rep[i * 2] = pt[0];
        rep[i * 2 + 1] = pt[1];
    }
    return ([_reducer(lep), _reducer(rep)], seeds % 5);
}

// File: contracts/Nose.sol



// SPDX-License-Identifier: MIT
pragma solidity ^0.8.4;
import "./Util.sol";

function _getNose(uint256 seeds) pure returns (string memory) {
    uint256 hei = ((seeds % 33) * 80) / 33 + 80;
    uint256 wid = (((seeds / 33) % 33) * 50) / 33 + 50;
    uint256 x = 400;
    uint256[6] memory pt = [x, 450 - hei, x + wid, 450, x - wid, 450];
    string memory ret = "";
    for (uint256 i = 0; i < pt.length; i += 2) {
        ret = string(
            abi.encodePacked(
                ret,
                i == 0 ? "M" : "L",
                Util.toStr(pt[i]),
                ",",
                Util.toStr(pt[i + 1])
            )
        );
    }
    ret = string(abi.encodePacked(ret, "Z"));
    return ret;
}
// File: @openzeppelin/contracts/token/ERC721/IERC721.sol



// SPDX-License-Identifier: MIT

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

    /**
     * @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 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);

    /**
     * @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;
}

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



// SPDX-License-Identifier: MIT

pragma solidity ^0.8.0;

/**
 * @title ERC721 token receiver interface
 * @dev Interface for any contract that wants to support safeTransfers
 * from ERC721 asset contracts.
 */
interface IERC721Receiver {
    /**
     * @dev Whenever an {IERC721} `tokenId` token is transferred to this contract via {IERC721-safeTransferFrom}
     * by `operator` from `from`, this function is called.
     *
     * It must return its Solidity selector to confirm the token transfer.
     * If any other value is returned or the interface is not implemented by the recipient, the transfer will be reverted.
     *
     * The selector can be obtained in Solidity with `IERC721.onERC721Received.selector`.
     */
    function onERC721Received(
        address operator,
        address from,
        uint256 tokenId,
        bytes calldata data
    ) external returns (bytes4);
}

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



// SPDX-License-Identifier: MIT

pragma solidity ^0.8.0;

import "../IERC721.sol";

/**
 * @title ERC-721 Non-Fungible Token Standard, optional metadata extension
 * @dev See https://eips.ethereum.org/EIPS/eip-721
 */
interface IERC721Metadata is IERC721 {
    /**
     * @dev Returns the token collection name.
     */
    function name() external view returns (string memory);

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

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

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



// SPDX-License-Identifier: MIT

pragma solidity ^0.8.0;

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

        uint256 size;
        assembly {
            size := extcodesize(account)
        }
        return size > 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

                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

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

pragma solidity ^0.8.0;

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

    /**
     * @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);
    }
}

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



// SPDX-License-Identifier: MIT

pragma solidity ^0.8.0;

import "./IERC165.sol";

/**
 * @dev Implementation of the {IERC165} interface.
 *
 * Contracts that want to implement ERC165 should inherit from this contract and override {supportsInterface} to check
 * for the additional interface id that will be supported. For example:
 *
 * ```solidity
 * function supportsInterface(bytes4 interfaceId) public view virtual override returns (bool) {
 *     return interfaceId == type(MyInterface).interfaceId || super.supportsInterface(interfaceId);
 * }
 * ```
 *
 * Alternatively, {ERC165Storage} provides an easier to use but more expensive implementation.
 */
abstract contract ERC165 is IERC165 {
    /**
     * @dev See {IERC165-supportsInterface}.
     */
    function supportsInterface(bytes4 interfaceId) public view virtual override returns (bool) {
        return interfaceId == type(IERC165).interfaceId;
    }
}

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



// SPDX-License-Identifier: MIT

pragma solidity ^0.8.0;

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

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



// SPDX-License-Identifier: MIT

pragma solidity ^0.8.0;

import "../IERC721.sol";

/**
 * @title ERC-721 Non-Fungible Token Standard, optional enumeration extension
 * @dev See https://eips.ethereum.org/EIPS/eip-721
 */
interface IERC721Enumerable is IERC721 {
    /**
     * @dev Returns the total amount of tokens stored by the contract.
     */
    function totalSupply() external view returns (uint256);

    /**
     * @dev Returns a token ID owned by `owner` at a given `index` of its token list.
     * Use along with {balanceOf} to enumerate all of ``owner``'s tokens.
     */
    function tokenOfOwnerByIndex(address owner, uint256 index) external view returns (uint256 tokenId);

    /**
     * @dev Returns a token ID at a given `index` of all the tokens stored by the contract.
     * Use along with {totalSupply} to enumerate all tokens.
     */
    function tokenByIndex(uint256 index) external view returns (uint256);
}