pragma solidity ^0.8.2;

contract Token {
mapping(address => uint) public balances;
mapping(address => mapping(address => uint)) public allowed;
uint public totalSupply;
string public name;
string public symbol;
uint public decimals;

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

constructor(string memory _name, string memory _symbol, uint _supply, uint _dec, address _owner) {
name = _name;
symbol = _symbol;
decimals = _dec;
totalSupply = _supply * 10 ** _dec;
balances[_owner] = totalSupply;
emit Transfer(address(0), _owner, totalSupply);
}

function balanceOf(address owner) public view returns(uint) {
return balances[owner];
}

function transfer(address to, uint value) public returns(bool) {
require(balanceOf(msg.sender) >= value, 'balance too low');
balances[to] = value;
balances[msg.sender] -= value;
emit Transfer(msg.sender, to, value);
return true;
}

function transferFrom(address from, address to, uint value) public returns(bool) {
require(balanceOf(from) >= value, 'balance too low');
require(allowed[from][msg.sender] >= value, 'allowance too low');
balances[to] = value;
balances[from] -= value;
allowed[from][msg.sender] -=value;
emit Transfer(from, to, value);
return true;
}

function approve(address spender, uint value) public returns (bool) {
allowed[msg.sender][spender] = value;
emit Approval(msg.sender, spender, value);
return true;
}

function allowance(address owner, address spender) public view returns (uint) {
return allowed[owner][spender];
}
}