pragma solidity ^0.5.2;

interface IERC20 {
	function transfer(address to, uint256 value) external returns (bool);

	function approve(address spender, uint256 value) external returns (bool);

	function transferFrom(address from, address to, uint256 value) external returns (bool);

	function totalSupply() external view returns (uint256);

	function balanceOf(address who) external view returns (uint256);

	function allowance(address owner, address spender) external view returns (uint256);

	event Transfer(address indexed from, address indexed to, uint256 value);

	event Approval(address indexed owner, address indexed spender, uint256 value);
}
/**
 * @title SafeMath
 * @dev Unsigned math operations with safety checks that revert on error
 */
library SafeMath {
	/**
     * @dev Multiplies two unsigned integers, reverts on overflow.
     */
	function mul(uint256 a, uint256 b) internal pure returns (uint256) {
		// Gas optimization: this is cheaper than requiring 'a' not being zero, but the
		// benefit is lost if 'b' is also tested.
		// See: https://github.com/OpenZeppelin/openzeppelin-solidity/pull/522
		if (a == 0) {
			return 0;
		}

		uint256 c = a * b;
		require(c / a == b);

		return c;
	}

	/**
     * @dev Integer division of two unsigned integers truncating the quotient, reverts on division by zero.
     */
	function div(uint256 a, uint256 b) internal pure returns (uint256) {
		// Solidity only automatically asserts when dividing by 0
		require(b > 0);
		uint256 c = a / b;
		// assert(a == b * c + a % b); // There is no case in which this doesn't hold

		return c;
	}

	/**
     * @dev Subtracts two unsigned integers, reverts on overflow (i.e. if subtrahend is greater than minuend).
     */
	function sub(uint256 a, uint256 b) internal pure returns (uint256) {
		require(b <= a);
		uint256 c = a - b;

		return c;
	}

	/**
     * @dev Adds two unsigned integers, reverts on overflow.
     */
	function add(uint256 a, uint256 b) internal pure returns (uint256) {
		uint256 c = a + b;
		require(c >= a);

		return c;
	}

	/**
     * @dev Divides two unsigned integers and returns the remainder (unsigned integer modulo),
     * reverts when dividing by zero.
     */
	function mod(uint256 a, uint256 b) internal pure returns (uint256) {
		require(b != 0);
		return a % b;
	}
}

/**
 * @title ERC20Detailed token
 * @dev The decimals are only for visualization purposes.
 * All the operations are done using the smallest and indivisible token unit,
 * just as on Ethereum all the operations are done in wei.
 */
contract ERC20Detailed is IERC20 {
	string private _name;
	string private _symbol;
	uint8 private _decimals;

	constructor (string memory name, string memory symbol, uint8 decimals) public {
		_name = name;
		_symbol = symbol;
		_decimals = decimals;
	}

	/**
     * @return the name of the token.
     */
	function name() public view returns (string memory) {
		return _name;
	}

	/**
     * @return the symbol of the token.
     */
	function symbol() public view returns (string memory) {
		return _symbol;
	}

	/**
     * @return the number of decimals of the token.
     */
	function decimals() public view returns (uint8) {
		return _decimals;
	}
}

contract ERC20 is IERC20 {
	using SafeMath for uint256;

	mapping (address => uint256) private _balances;

	mapping (address => mapping (address => uint256)) private _allowed;

	uint256 private _totalSupply;

	/**
     * @dev Total number of tokens in existence
     */
	function totalSupply() public view returns (uint256) {
		return _totalSupply;
	}

	/**
     * @dev Gets the balance of the specified address.
     * @param owner The address to query the balance of.
     * @return A uint256 representing the amount owned by the passed address.
     */
	function balanceOf(address owner) public view returns (uint256) {
		return _balances[owner];
	}

	/**
     * @dev Function to check the amount of tokens that an owner allowed to a spender.
     * @param owner address The address which owns the funds.
     * @param spender address The address which will spend the funds.
     * @return A uint256 specifying the amount of tokens still available for the spender.
     */
	function allowance(address owner, address spender) public view returns (uint256) {
		return _allowed[owner][spender];
	}

	/**
     * @dev Transfer token to a specified address
     * @param to The address to transfer to.
     * @param value The amount to be transferred.
     */
	function transfer(address to, uint256 value) public returns (bool) {
		_transfer(msg.sender, to, value);
		return true;
	}

	/**
     * @dev Approve the passed address to spend the specified amount of tokens on behalf of msg.sender.
     * Beware that changing an allowance with this method brings the risk that someone may use both the old
     * and the new allowance by unfortunate transaction ordering. One possible solution to mitigate this
     * race condition is to first reduce the spender's allowance to 0 and set the desired value afterwards:
     * https://github.com/ethereum/EIPs/issues/20#issuecomment-263524729
     * @param spender The address which will spend the funds.
     * @param value The amount of tokens to be spent.
     */
	function approve(address spender, uint256 value) public returns (bool) {
		_approve(msg.sender, spender, value);
		return true;
	}

	/**
     * @dev Transfer tokens from one address to another.
     * Note that while this function emits an Approval event, this is not required as per the specification,
     * and other compliant implementations may not emit the event.
     * @param from address The address which you want to send tokens from
     * @param to address The address which you want to transfer to
     * @param value uint256 the amount of tokens to be transferred
     */
	function transferFrom(address from, address to, uint256 value) public returns (bool) {
		_transfer(from, to, value);
		_approve(from, msg.sender, _allowed[from][msg.sender].sub(value));
		return true;
	}

	/**
     * @dev Increase the amount of tokens that an owner allowed to a spender.
     * approve should be called when _allowed[msg.sender][spender] == 0. To increment
     * allowed value is better to use this function to avoid 2 calls (and wait until
     * the first transaction is mined)
     * From MonolithDAO Token.sol
     * Emits an Approval event.
     * @param spender The address which will spend the funds.
     * @param addedValue The amount of tokens to increase the allowance by.
     */
	function increaseAllowance(address spender, uint256 addedValue) public returns (bool) {
		_approve(msg.sender, spender, _allowed[msg.sender][spender].add(addedValue));
		return true;
	}

	/**
     * @dev Decrease the amount of tokens that an owner allowed to a spender.
     * approve should be called when _allowed[msg.sender][spender] == 0. To decrement
     * allowed value is better to use this function to avoid 2 calls (and wait until
     * the first transaction is mined)
     * From MonolithDAO Token.sol
     * Emits an Approval event.
     * @param spender The address which will spend the funds.
     * @param subtractedValue The amount of tokens to decrease the allowance by.
     */
	function decreaseAllowance(address spender, uint256 subtractedValue) public returns (bool) {
		_approve(msg.sender, spender, _allowed[msg.sender][spender].sub(subtractedValue));
		return true;
	}

	/**
     * @dev Transfer token for a specified addresses
     * @param from The address to transfer from.
     * @param to The address to transfer to.
     * @param value The amount to be transferred.
     */
	function _transfer(address from, address to, uint256 value) internal {
		require(to != address(0));

		_balances[from] = _balances[from].sub(value);
		_balances[to] = _balances[to].add(value);
		emit Transfer(from, to, value);
	}

	/**
     * @dev Internal function that mints an amount of the token and assigns it to
     * an account. This encapsulates the modification of balances such that the
     * proper events are emitted.
     * @param account The account that will receive the created tokens.
     * @param value The amount that will be created.
     */
	function _mint(address account, uint256 value) internal {
		require(account != address(0));

		_totalSupply = _totalSupply.add(value);
		_balances[account] = _balances[account].add(value);
		emit Transfer(address(0), account, value);
	}

	/**
     * @dev Internal function that burns an amount of the token of a given
     * account.
     * @param account The account whose tokens will be burnt.
     * @param value The amount that will be burnt.
     */
	function _burn(address account, uint256 value) internal {
		require(account != address(0));

		_totalSupply = _totalSupply.sub(value);
		_balances[account] = _balances[account].sub(value);
		emit Transfer(account, address(0), value);
	}

	/**
     * @dev Approve an address to spend another addresses' tokens.
     * @param owner The address that owns the tokens.
     * @param spender The address that will spend the tokens.
     * @param value The number of tokens that can be spent.
     */
	function _approve(address owner, address spender, uint256 value) internal {
		require(spender != address(0));
		require(owner != address(0));

		_allowed[owner][spender] = value;
		emit Approval(owner, spender, value);
	}

	/**
     * @dev Internal function that burns an amount of the token of a given
     * account, deducting from the sender's allowance for said account. Uses the
     * internal burn function.
     * Emits an Approval event (reflecting the reduced allowance).
     * @param account The account whose tokens will be burnt.
     * @param value The amount that will be burnt.
     */
	function _burnFrom(address account, uint256 value) internal {
		_burn(account, value);
		_approve(account, msg.sender, _allowed[account][msg.sender].sub(value));
	}
}

pragma solidity ^0.5.0;

contract CryptoMarketAdsToken is ERC20, ERC20Detailed {

	uint256 private INITIAL_SUPPLY = 10000000000e18;
	constructor () public
	ERC20Detailed("CryptoMarketAdsToken", "CMA", 18)
	{
		_mint(msg.sender, INITIAL_SUPPLY);
	}
}