using System;               

public class Program

{

    public static void Main()

    {

   Console.WriteLine("a=");

    int a = int.Parse(Console.ReadLine());

   Console.WriteLine("b=");

    int b = int.Parse(Console.ReadLine());   

        if(b>a)

        {

            int x =a;

            a=b;

            b=x;

        }

        while(b!=0)

        {

            int r = a%b;

            a=b;

            b=r;

        }

        Console.WriteLine(a);

​

}}

​

​