pragma solidity ^0.6.12;
// SPDX-License-Identifier: Unlicensed
interface IERC20 {

    function totalSupply() external view returns (uint256);

    function balanceOf(address account) external view returns (uint256);

    function transfer(address recipient, uint256 amount) external returns (bool);

    function allowance(address owner, address spender) external view returns (uint256);

    function approve(address spender, uint256 amount) external returns (bool);

    function transferFrom(address sender, address recipient, uint256 amount) external returns (bool);

    event Transfer(address indexed from, address indexed to, uint256 value);

    event Approval(address indexed owner, address indexed spender, uint256 value);
}

library SafeMath {

    function add(uint256 a, uint256 b) internal pure returns (uint256) {
        uint256 c = a + b;
        require(c >= a, "SafeMath: addition overflow");

        return c;
    }

    function sub(uint256 a, uint256 b) internal pure returns (uint256) {
        return sub(a, b, "SafeMath: subtraction overflow");
    }

    function sub(uint256 a, uint256 b, string memory errorMessage) internal pure returns (uint256) {
        require(b <= a, errorMessage);
        uint256 c = a - b;

        return c;
    }

    function mul(uint256 a, uint256 b) internal pure returns (uint256) {

        if (a == 0) {
            return 0;
        }

        uint256 c = a * b;
        require(c / a == b, "SafeMath: multiplication overflow");

        return c;
    }

    function div(uint256 a, uint256 b) internal pure returns (uint256) {
        return div(a, b, "SafeMath: division by zero");
    }

    function div(uint256 a, uint256 b, string memory errorMessage) internal pure returns (uint256) {
        require(b > 0, errorMessage);
        uint256 c = a / b;
        // assert(a == b * c + a % b); // There is no case in which this doesn't hold

        return c;
    }

    function mod(uint256 a, uint256 b) internal pure returns (uint256) {
        return mod(a, b, "SafeMath: modulo by zero");
    }

    function mod(uint256 a, uint256 b, string memory errorMessage) internal pure returns (uint256) {
        require(b != 0, errorMessage);
        return a % b;
    }
}

abstract contract Context {
    function _msgSender() internal view virtual returns (address payable) {
        return msg.sender;
    }

    function _msgData() internal view virtual returns (bytes memory) {
        this; // silence state mutability warning without generating bytecode - see https://github.com/ethereum/solidity/issues/2691
        return msg.data;
    }
}

contract Ownable is Context {
  address private _owner;
  address private _previousOwner;

  event OwnershipTransferred(address indexed previousOwner, address indexed newOwner);

  constructor () internal {
    address msgSender = _msgSender();
    _owner = msgSender;
    emit OwnershipTransferred(address(0), msgSender);
  }

  function owner() public view returns (address) {
    return _owner;
  }

  modifier onlyOwner() {
    require(_owner == _msgSender(), "Ownable: caller is not the owner");
    _;
  }

  function renounceOwnership() public virtual onlyOwner {
    emit OwnershipTransferred(_owner, address(0));
    _owner = address(0);
  }


  function transferOwnership(address newOwner) public virtual onlyOwner {
    require(newOwner != address(0), "Ownable: new owner is the zero address");
    emit OwnershipTransferred(_owner, newOwner);
    _owner = newOwner;
  }
}


contract eightCoin is Context, IERC20, Ownable {
  using SafeMath for uint256;

  mapping (address => uint256) private _balances;
  mapping (address => mapping (address => uint256)) private _allowances;

  uint8 private _decimals = 2; //number of decimal places
  uint256 private _totalSupply = 8000000000 * 10**2;
  string private _symbol = "8coin";
  string private _name = "8 Coin";

  constructor() public {
    _balances[_msgSender()] = _totalSupply;
    emit Transfer(address(0), _msgSender(), _totalSupply);
  }

  function getOwner() external view returns (address) {
    return owner();
  }

  function decimals() external view returns (uint8) {
    return _decimals;
  }

  function symbol() external view returns (string memory) {
    return _symbol;
  }
 
  function name() external view returns (string memory) {
    return _name;
  }

  function totalSupply() external view override returns (uint256) {
    return _totalSupply;
  }

  function balanceOf(address account) external view override returns (uint256) {
    return _balances[account];
  }

  function transfer(address recipient, uint256 amount) external override returns (bool) {
    _transfer(_msgSender(), recipient, amount);
    return true;
  }

  function allowance(address owner, address spender) external view override returns (uint256) {
    return _allowances[owner][spender];
  }

  function approve(address spender, uint256 amount) external override returns (bool) {
    _approve(_msgSender(), spender, amount);
    return true;
  }

  function transferFrom(address sender, address recipient, uint256 amount) external override returns (bool) {
    _transfer(sender, recipient, amount);
    _approve(sender, _msgSender(), _allowances[sender][_msgSender()].sub(amount, "transfer amount exceeds allowance"));
    return true;
  }


  function increaseAllowance(address spender, uint256 addedValue) public returns (bool) {
    _approve(_msgSender(), spender, _allowances[_msgSender()][spender].add(addedValue));
    return true;
  }

  function decreaseAllowance(address spender, uint256 subtractedValue) public returns (bool) {
    _approve(_msgSender(), spender, _allowances[_msgSender()][spender].sub(subtractedValue, "error in decrease allowance"));
    return true;
  }

  function _transfer(address sender, address recipient, uint256 amount) internal {
    require(sender != address(0), "transfer sender address is 0 address");
    require(recipient != address(0), "transfer recipient address is 0 address");

    _balances[sender] = _balances[sender].sub(amount, "transfer balance too low");
    _balances[recipient] = _balances[recipient].add(amount);
    emit Transfer(sender, recipient, amount);
  }

  function _approve(address owner, address spender, uint256 amount) internal {
    require(owner != address(0), "approve owner is 0 address");
    require(spender != address(0), "approve spender is 0 address");

    _allowances[owner][spender] = amount;
    emit Approval(owner, spender, amount);
  }

}