using System;

namespace Euklides
{

    class Euklides
    {
        public static int nwd(int x, int y)
        {
            if (x != y)
            {

                if (x > y)
                {
                    x = x - y;
                }
                else
                {
                    y = y - x;
                }
                nwd(x, y);
            }

            return ((x < y) ? x : y);

        }

        public static void Main(string[] args)
        {

            int a, b;

            Console.Write("a = ");
            a = int.Parse(Console.ReadLine());
            Console.Write("b = ");
            b = int.Parse(Console.ReadLine());

            var eu = new Euklides();
            Console.WriteLine("NWD = " + nwd(a, b));
            Console.Write("Press any key to continue . . . ");
            Console.ReadKey(true);
        }

    }

}