using System;

public class main {

    public static void Main(String[] args) {
        String[] scan = new String[2];
        scan = Console.ReadLine().Split(' ');
        int m = Convert.ToInt32(scan[0]);
        int n = Convert.ToInt32(scan[1]);
        int r;
        while (n != 0) {
            r = m%n;
            m = n;
            n = r;
        }
        Console.WriteLine(m);
        Console.ReadKey();
        return;
    }
}