public static boolean isPrime(long num)
	{
		if (num<2)
			return false;
		if (num==2)
			return true;
		if (num%2==0)
			return false;
		
		for (long i = 3; (i*i)<=(num); i+=2)
		{
			if (num%i == 0)
				return false;
		}
		
		return true;
	}