pragma solidity 0.5.3;

library SafeMath {
function add(uint a, uint b) internal pure returns(uint) {
uint c = a b;
require(c >= a, "Sum Overflow!");

return c;
}

function sub(uint a, uint b) internal pure returns(uint) {
require(b <= a, "Sub Underflow!");
uint c = a - b;

return c;
}

function mul(uint a, uint b) internal pure returns(uint) {
if(a == 0) {
return 0;
}

uint c = a * b;
require(c / a == b, "Mul Overflow!");

return c;
}

function div(uint a, uint b) internal pure returns(uint) {
uint c = a / b;

return c;
}
}

contract Ownable {
address payable public owner;

event OwnershipTransferred(address newOwner);

constructor() public {
owner = msg.sender;
}

modifier onlyOwner() {
require(msg.sender == owner, "You are not the owner!");
_;
}

function transferOwnership(address payable newOwner) onlyOwner public {
owner = newOwner;

emit OwnershipTransferred(owner);
}
}

contract ERC20 {
function totalSupply() public view returns (uint);
function balanceOf(address tokenOwner) public view returns (uint balance);
function allowance(address tokenOwner, address spender) public view returns (uint remaining);
function transfer(address to, uint tokens) public returns (bool success);
function approve(address spender, uint tokens) public returns (bool success);
function transferFrom(address from, address to, uint tokens) public returns (bool success);

event Transfer(address indexed from, address indexed to, uint tokens);
event Approval(address indexed tokenOwner, address indexed spender, uint tokens);
}

contract BasicToken is Ownable, ERC20 {
using SafeMath for uint;

uint internal _totalSupply;
mapping(address => uint) internal _balances;
mapping(address => mapping(address => uint)) internal _allowed;

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

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

function transfer(address to, uint tokens) public returns (bool success) {
require(_balances[msg.sender] >= tokens);
require(to != address(0));

_balances[msg.sender] = _balances[msg.sender].sub(tokens);
_balances[to] = _balances[to].add(tokens);

emit Transfer(msg.sender, to, tokens);

return true;
}

function approve(address spender, uint tokens) public returns (bool success) {
_allowed[msg.sender][spender] = tokens;

emit Approval(msg.sender, spender, tokens);

return true;
}

function allowance(address tokenOwner, address spender) public view returns (uint remaining) {
return _allowed[tokenOwner][spender];
}

function transferFrom(address from, address to, uint tokens) public returns (bool success) {
require(_allowed[from][msg.sender] >= tokens);
require(_balances[from] >= tokens);
require(to != address(0));

_balances[from] = _balances[from].sub(tokens);
_balances[to] = _balances[to].add(tokens);
_allowed[from][msg.sender] = _allowed[from][msg.sender].sub(tokens);

emit Transfer(from, to, tokens);

return true;
}
}

contract MintableToken is BasicToken {
event Mint(address indexed to, uint tokens);

function mint(address to, uint tokens) onlyOwner public {
_balances[to] = _balances[to].add(tokens);
_totalSupply = _totalSupply.add(tokens);

emit Mint(to, tokens);
}
}

contract TestCoin is MintableToken {
string public constant name = "Test Coin";
string public constant symbol = "TST";
uint8 public constant decimals = 18;
}

contract CarlosCoin is MintableToken {
string public constant name = "Lili Fox";
string public constant symbol = "LILI";
uint8 public constant decimals = 18;
}