interface IERC721 {


  /// @dev This emits when ownership of any NFT changes by any mechanism.
  ///  This event emits when NFTs are created (`from` == 0) and destroyed
  ///  (`to` == 0). Exception: during contract creation, any number of NFTs
  ///  may be created and assigned without emitting Transfer. At the time of
  ///  any transfer, the approved address for that NFT (if any) is reset to none.
  event Transfer(address indexed _from, address indexed _to, uint indexed _tokenId);

  /// @dev This emits when the approved address for an NFT is changed or
  ///  reaffirmed. The zero address indicates there is no approved address.
  ///  When a Transfer event emits, this also indicates that the approved
  ///  address for that NFT (if any) is reset to none.
  event Approval(address indexed _owner, address indexed _approved, uint indexed _tokenId);

  /// @dev This emits when an operator is enabled or disabled for an owner.
  ///  The operator can manage all NFTs of the owner.
  event ApprovalForAll(address indexed _owner, address indexed _operator, bool _approved);

  /// @notice Transfer ownership of an NFT -- THE CALLER IS RESPONSIBLE
  ///  TO CONFIRM THAT `_to` IS CAPABLE OF RECEIVING NFTS OR ELSE
  ///  THEY MAY BE PERMANENTLY LOST
  /// @dev Throws unless `msg.sender` is the current owner, an authorized
  ///  operator, or the approved address for this NFT. Throws if `_from` is
  ///  not the current owner. Throws if `_to` is the zero address. Throws if
  ///  `_tokenId` is not a valid NFT.
  /// @param _from The current owner of the NFT
  /// @param _to The new owner
  /// @param _tokenId The NFT to transfer
  function transferFrom(address _from, address _to, uint _tokenId) external;

  /// @notice Set or reaffirm the approved address for an NFT
  /// @dev The zero address indicates there is no approved address.
  /// @dev Throws unless `msg.sender` is the current NFT owner, or an authorized
  ///  operator of the current owner.
  /// @param _approved The new approved NFT controller
  /// @param _tokenId The NFT to approve
  function approve(address _approved, uint _tokenId) external payable;

  /// @notice Transfers the ownership of an NFT from one address to another address
  /// @dev Throws unless `msg.sender` is the current owner, an authorized
  ///  operator, or the approved address for this NFT. Throws if `_from` is
  ///  not the current owner. Throws if `_to` is the zero address. Throws if
  ///  `_tokenId` is not a valid NFT. When transfer is complete, this function
  ///  checks if `_to` is a smart contract (code size > 0). If so, it calls
  ///  `onERC721Received` on `_to` and throws if the return value is not
  ///  `bytes4(keccak256('onERC721Received(address,address,uint,bytes)'))`.
  /// @param _from The current owner of the NFT
  /// @param _to The new owner
  /// @param _tokenId The NFT to transfer
  /// @param data Additional data with no specified format, sent in call to `_to`
  function safeTransferFrom(address _from, address _to, uint _tokenId, bytes calldata data) external;

  /// @notice Transfers the ownership of an NFT from one address to another address
  /// @dev This works identically to the other function with an extra data parameter,
  ///  except this function just sets data to ''
  /// @param _from The current owner of the NFT
  /// @param _to The new owner
  /// @param _tokenId The NFT to transfer
  function safeTransferFrom(address _from, address _to, uint _tokenId) external;

  /// @notice Enable or disable approval for a third party ('operator') to manage
  ///  all of `msg.sender`'s assets.
  /// @dev Emits the ApprovalForAll event. The contract MUST allow
  ///  multiple operators per owner.
  /// @param _operator Address to add to the set of authorized operators.
  /// @param _approved True if the operator is approved, false to revoke approval
  function setApprovalForAll(address _operator, bool _approved) external;

  /// @notice Count all NFTs assigned to an owner
  /// @dev NFTs assigned to the zero address are considered invalid, and this
  ///  function throws for queries about the zero address.
  /// @param _owner An address for whom to query the balance
  /// @return The number of NFTs owned by `_owner`, possibly zero
  function balanceOf(address _owner) external view returns (uint);

  /// @notice Find the owner of an NFT
  /// @dev NFTs assigned to zero address are considered invalid, and queries
  ///  about them do throw.
  /// @param _tokenId The identifier for an NFT
  /// @return The address of the owner of the NFT
  function ownerOf(uint _tokenId) external view returns (address);

  /// @notice Get the approved address for a single NFT
  /// @dev Throws if `_tokenId` is not a valid NFT
  /// @param _tokenId The NFT to find the approved address for
  /// @return The approved address for this NFT, or the zero address if there is none
  function getApproved(uint _tokenId) external view returns (address);

  /// @notice Query if an address is an authorized operator for another address
  /// @param _owner The address that owns the NFTs
  /// @param _operator The address that acts on behalf of the owner
  /// @return True if `_operator` is an approved operator for `_owner`, false otherwise
  function isApprovedForAll(address _owner, address _operator) external view returns (bool);

  /// @notice A descriptive name for a collection of NFTs in this contract
  function name() external view returns (string memory _name);
}
/// @title ERC-721 Non-Fungible Token Standard
/// @dev See https://eips.ethereum.org/EIPS/eip-721
///  Note: the ERC-165 identifier for this interface is 0x80ac58cd
function approve(address _approved, uint _tokenId) external payable;

/// @notice Set or reaffirm the approved address for an NFT
/// @dev The zero address indicates there is no approved address.
/// @dev Throws unless `msg.sender` is the current NFT owner, or an authorized
///  operator of the current owner.
/// @param _approved The new approved NFT controller
/// @param _tokenId The NFT to approve