int a = Convert.ToInt32(Console.ReadLine());
            int b = Convert.ToInt32(Console.ReadLine());
            a = Math.Max(a, b);
            b = Math.Min(a, b);

            if (a != b)
            {
                while(a > b)
                {
                    a = a - b;
                }
            }
            Console.WriteLine(a);
            Console.ReadLine();