library SafeMath {
	
	/**
	* @dev Multiplies two numbers, throws on overflow.
	*/
	function mul(uint256 a, uint256 b) internal pure returns (uint256) {
		if (a == 0) {
			return 0;
		}
		uint256 c = a * b;
		assert(c / a == b);
		return c;
	}
	
	
	/**
	* @dev Integer division of two numbers, truncating the quotient.
	*/
	function div(uint256 a, uint256 b) internal pure returns (uint256) {
		uint256 c = a / b;
		return c;
	}
	
	
	/**
	* @dev Substracts two numbers, throws on overflow (i.e. if subtrahend is greater than minuend).
	*/
	function sub(uint256 a, uint256 b) internal pure returns (uint256) {
		assert(b <= a);
		return a - b;
	}
	
	
	/**
	* @dev Adds two numbers, throws on overflow.
	*/
	function add(uint256 a, uint256 b) internal pure returns (uint256) {
		uint256 c = a + b;
		assert(c >= a);
		return c;
	}
	
	
	/**
	* @dev Powers the first number to the second, throws on overflow.
	*/
	function pow(uint a, uint b) internal pure returns (uint) {
		if (b == 0) {
			return 1;
		}
		uint c = a ** b;
		assert(c >= a);
		return c;
	}
	
	
	/**
	 * @dev Multiplies the given number by 10**decimals
	 */
	function withDecimals(uint number, uint decimals) internal pure returns (uint) {
		return mul(number, pow(10, decimals));
	}
	
}
/**
 * @title SafeMath
 * @dev Math operations with safety checks that throw on error
 */
function mul(uint256 a, uint256 b) internal pure returns (uint256) {
	if (a == 0) {
		return 0;
	}
	uint256 c = a * b;
	assert(c / a == b);
	return c;
}

/**
 	* @dev Multiplies two numbers, throws on overflow.
 	*/