#include <iostream>
#include <fstream>
using namespace std;
ifstream in ("cmmdc.in");
ofstream out ("cmmdc.out");
int euclid(int a, int b)
{
    if(b!=0)
        {

        euclid(b,a%b);

        }
    else
        return a;

}
int main()
{
    int a=0,b=0;

    in>>a>>b;

    int t=euclid(a,b);

    if(t!=1)
        out<<t;
    else
        out<<0;

    return 0;
}