// SPDX-License-Identifier: MIT

// File: @openzeppelin/contracts/utils/Counters.sol


// OpenZeppelin Contracts v4.4.1 (utils/Counters.sol)

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/Strings.sol


// OpenZeppelin Contracts v4.4.1 (utils/Strings.sol)

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/Context.sol


// OpenZeppelin Contracts v4.4.1 (utils/Context.sol)

pragma solidity ^0.8.0;

/**
* @dev Provides information about the current execution context, including the
* sender of the transaction and its data. While these are generally available
* via msg.sender and msg.data, they should not be accessed in such a direct
* manner, since when dealing with meta-transactions the account sending and
* paying for execution may not be the actual sender (as far as an application
* is concerned).
*
* This contract is only required for intermediate, library-like contracts.
*/
abstract contract Context {
   function _msgSender() internal view virtual returns (address) {
       return msg.sender;
   }

   function _msgData() internal view virtual returns (bytes calldata) {
       return msg.data;
   }
}

// File: @openzeppelin/contracts/access/Ownable.sol


// OpenZeppelin Contracts v4.4.1 (access/Ownable.sol)

pragma solidity ^0.8.0;


/**
* @dev Contract module which provides a basic access control mechanism, where
* there is an account (an owner) that can be granted exclusive access to
* specific functions.
*
* By default, the owner account will be the one that deploys the contract. This
* can later be changed with {transferOwnership}.
*
* This module is used through inheritance. It will make available the modifier
* `onlyOwner`, which can be applied to your functions to restrict their use to
* the owner.
*/
abstract contract Ownable is Context {
   address private _owner;

   event OwnershipTransferred(address indexed previousOwner, address indexed newOwner);

   /**
    * @dev Initializes the contract setting the deployer as the initial owner.
    */
   constructor() {
       _transferOwnership(_msgSender());
   }

   /**
    * @dev 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 {
       _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/utils/Address.sol


// OpenZeppelin Contracts (last updated v4.5.0) (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

               assembly {
                   let returndata_size := mload(returndata)
                   revert(add(32, returndata), returndata_size)
               }
           } else {
               revert(errorMessage);
           }
       }
   }
}

// File: @openzeppelin/contracts/token/ERC721/IERC721Receiver.sol


// OpenZeppelin Contracts v4.4.1 (token/ERC721/IERC721Receiver.sol)

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/utils/introspection/IERC165.sol


// 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: @openzeppelin/contracts/utils/introspection/ERC165.sol


// OpenZeppelin Contracts v4.4.1 (utils/introspection/ERC165.sol)

pragma solidity ^0.8.0;


/**
* @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/token/ERC721/IERC721.sol


// OpenZeppelin Contracts v4.4.1 (token/ERC721/IERC721.sol)

pragma solidity ^0.8.0;


/**
* @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/extensions/IERC721Metadata.sol


// OpenZeppelin Contracts v4.4.1 (token/ERC721/extensions/IERC721Metadata.sol)

pragma solidity ^0.8.0;


/**
* @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/token/ERC721/ERC721.sol


// OpenZeppelin Contracts (last updated v4.5.0) (token/ERC721/ERC721.sol)

pragma solidity ^0.8.0;








/**
* @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 {
       _setApprovalForAll(_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);

       _afterTokenTransfer(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);

       _afterTokenTransfer(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 from incorrect owner");
       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);

       _afterTokenTransfer(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 Approve `operator` to operate on all of `owner` tokens
    *
    * Emits a {ApprovalForAll} event.
    */
   function _setApprovalForAll(
       address owner,
       address operator,
       bool approved
   ) internal virtual {
       require(owner != operator, "ERC721: approve to caller");
       _operatorApprovals[owner][operator] = approved;
       emit ApprovalForAll(owner, operator, approved);
   }

   /**
    * @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 {}

   /**
    * @dev Hook that is called after any transfer of tokens. This includes
    * minting and burning.
    *
    * Calling conditions:
    *
    * - when `from` and `to` are both non-zero.
    * - `from` and `to` are never both zero.
    *
    * To learn more about hooks, head to xref:ROOT:extending-contracts.adoc#using-hooks[Using Hooks].
    */
   function _afterTokenTransfer(
       address from,
       address to,
       uint256 tokenId
   ) internal virtual {}
}

// File: contracts/abc.sol

pragma solidity >=0.7.0 <0.9.0;




contract StrongDragons is ERC721, Ownable {
 using Strings for uint256;
 using Counters for Counters.Counter;

 Counters.Counter private supply;

 string public uriPrefix = "";
 string public uriSuffix = ".json";
 string public hiddenMetadataUri;

 uint256 public cost = 0.05 ether;
 uint256 public maxSupply = 10000;
 uint256 public maxMintAmountPerTx = 10 ;
  uint256 public maxMintAmount = 150;

 bool public paused = true;
 bool public revealed = false;

 constructor() ERC721("STRONG DRAGONS", "DRGNS") {
   setHiddenMetadataUri("ipfs://QmUFTrnvXsuRcdyc5XEizFtxHjyXEYzSywrtyZBAnEXdBe/hidden_Dragon_Metadata.json");
 }

 modifier mintCompliance(uint256 _mintAmount) {
   require(_mintAmount > 0 && _mintAmount <= maxMintAmountPerTx, "Invalid mint amount!");
   require(supply.current() + _mintAmount <= maxSupply, "Max supply exceeded!");
   require(balanceOf(msg.sender) < 150, 'You have reached the max wallet limit');
   require(_mintAmount <= maxMintAmount, 'transaction exceeds the maximum amount of tokens');
   _;
 }

 function totalSupply() public view returns (uint256) {
   return supply.current();
 }

 function mint(uint256 _mintAmount) public payable mintCompliance(_mintAmount) {
   require(!paused, "The contract is paused!");
   require(msg.value >= cost * _mintAmount, "Insufficient funds!");

   _mintLoop(msg.sender, _mintAmount);
 }

  function mintForAddress(uint256 _mintAmount, address _receiver) public mintCompliance(_mintAmount) onlyOwner {
   _mintLoop(_receiver, _mintAmount);
 }

 function walletOfOwner(address _owner)
   public
   view
   returns (uint256[] memory)
 {
   uint256 ownerTokenCount = balanceOf(_owner);
   uint256[] memory ownedTokenIds = new uint256[](ownerTokenCount);
   uint256 currentTokenId = 1;
   uint256 ownedTokenIndex = 0;

   while (ownedTokenIndex < ownerTokenCount && currentTokenId <= maxSupply) {
     address currentTokenOwner = ownerOf(currentTokenId);

     if (currentTokenOwner == _owner) {
       ownedTokenIds[ownedTokenIndex] = currentTokenId;

       ownedTokenIndex++;
     }

     currentTokenId++;
   }

   return ownedTokenIds;
 }

 function tokenURI(uint256 _tokenId)
   public
   view
   virtual
   override
   returns (string memory)
 {
   require(
     _exists(_tokenId),
     "ERC721Metadata: URI query for nonexistent token"
   );

   if (revealed == false) {
     return hiddenMetadataUri;
   }

   string memory currentBaseURI = _baseURI();
   return bytes(currentBaseURI).length > 0
       ? string(abi.encodePacked(currentBaseURI, _tokenId.toString(), uriSuffix))
       : "";
 }

 function setRevealed(bool _state) public onlyOwner {
   revealed = _state;
 }

 function setCost(uint256 _cost) public onlyOwner {
   cost = _cost;
 }

 function setMaxMintAmountPerTx(uint256 _maxMintAmountPerTx) public onlyOwner {
   maxMintAmountPerTx = _maxMintAmountPerTx;
 }

 function setHiddenMetadataUri(string memory _hiddenMetadataUri) public onlyOwner {
   hiddenMetadataUri = _hiddenMetadataUri;
 }

 function setUriPrefix(string memory _uriPrefix) public onlyOwner {
   uriPrefix = _uriPrefix;
 }

 function setUriSuffix(string memory _uriSuffix) public onlyOwner {
   uriSuffix = _uriSuffix;
 }

 function setPaused(bool _state) public onlyOwner {
   paused = _state;
 }

 function withdraw() public onlyOwner {

   // This will transfer the remaining contract balance to the owner.
   // Do not remove this otherwise you will not be able to withdraw the funds.
   // =============================================================================
   (bool os, ) = payable(owner()).call{value: address(this).balance}("");
   require(os);
   // =============================================================================
 }

 function _mintLoop(address _receiver, uint256 _mintAmount) internal {
   for (uint256 i = 0; i < _mintAmount; i++) {
     supply.increment();
     _safeMint(_receiver, supply.current());
   }
 }

 function _baseURI() internal view virtual override returns (string memory) {
   return uriPrefix;
 }
}