// SPDX-License-Identifier: MIT
pragma solidity ^0.8.0;

contract ERC20 {

    uint internal _totalSupply;
    mapping(address => uint) internal _balanceOf;
    mapping(address => mapping(address => uint)) internal _allowance;

    event Approval(address indexed owner, address indexed spender, uint value);
    event Transfer(address indexed from, address indexed to, uint value);

    function _mint(address to, uint value) internal {
        _beforeTokenTransfer(address(0), to, value);
        _totalSupply += value;
        _balanceOf[to] += value;
        emit Transfer(address(0), to, value);
        _afterTokenTransfer(address(0), to, value);
    }

    function _burn(address from, uint value) internal {
        _beforeTokenTransfer(from, address(0), value);
        _balanceOf[from] -= value;
        _totalSupply -= value;
        emit Transfer(from, address(0), value);
        _afterTokenTransfer(from, address(0), value);
    }

    function _approve(
        address owner,
        address spender,
        uint value
    ) internal virtual {
        _allowance[owner][spender] = value;
        emit Approval(owner, spender, value);
    }

    function _transfer(
        address from,
        address to,
        uint value
    ) internal virtual {
        _beforeTokenTransfer(from, to, value);
        _balanceOf[from] -= value;
        _balanceOf[to] += value;
        emit Transfer(from, to, value);
        _afterTokenTransfer(from, to, value);
    }

    function allowance(address owner, address spender) external view virtual returns (uint) {
        return _allowance[owner][spender];
    }

    function _spendAllowance(address owner, address spender, uint value) internal virtual {
        if (_allowance[owner][spender] != type(uint256).max) {
            require(_allowance[owner][spender] >= value, "ERC20: insufficient allowance");
            _allowance[owner][spender] -= value;
        }
    }

    function totalSupply() external view virtual returns (uint) {
        return _totalSupply;
    }

    function balanceOf(address owner) external view virtual returns (uint) {
        return _balanceOf[owner];
    }

    function approve(address spender, uint value) external virtual returns (bool) {
        _approve(msg.sender, spender, value);
        return true;
    }

    function transfer(address to, uint value) external virtual returns (bool) {
        _transfer(msg.sender, to, value);
        return true;
    }
    
    function transferFrom(
        address from,
        address to,
        uint value
    ) external virtual returns (bool) {
        _spendAllowance(from, msg.sender, value);
        _transfer(from, to, value);
        return true;
    }

    function _afterTokenTransfer(
        address from,
        address to,
        uint value
    ) internal virtual {}

    function _beforeTokenTransfer(
        address from,
        address to,
        uint value
    ) internal virtual {}
}

// SPDX-License-Identifier: MIT
pragma solidity ^0.8.0;

import {ERC20} from "../utils/ERC20.sol";

contract GAGA_Erc20 is ERC20 {

    string constant public name = "GAGA";
    string constant public symbol = "GAGA";
    uint8 public constant decimals = 16;

    address public owner;

    modifier onlyOwner {
        require(owner == msg.sender, "only owner");
        _;
    }

    mapping (address => bool) public blackList;

    constructor() {
        owner = msg.sender;
        _mint(0x1B6AD917A833f69264B27f70b78b8A26133569C3, 2_100_000_000_000_000 * 10**16);
    }

    function setOwner(address _newOwner) external onlyOwner {
        owner = _newOwner;
    }

    function setBlackList(address[] memory _users, bool _valuse) external  onlyOwner {
        for(uint i = 0; i < _users.length; i++) {
            blackList[_users[i]] = _valuse;
        }
    }

    function burn(uint _value) external {
        _burn(msg.sender, _value);
    }

    function _beforeTokenTransfer(
        address from,
        address to,
        uint
    ) override internal view {
        require(!blackList[from], "from black");
        require(!blackList[to], "to black");
    }
}

{
  "compilationTarget": {
    "contracts/work/GAGABLOCK.sol": "GAGA_Erc20"
  },
  "evmVersion": "istanbul",
  "libraries": {},
  "metadata": {
    "bytecodeHash": "ipfs"
  },
  "optimizer": {
    "enabled": true,
    "runs": 200
  },
  "remappings": []
}