#include <iostream>
#include <fstream>
using namespace std;

int main()
{
    int a, b;
    ifstream f("cmmdc.in");
    ofstream g("cmmdc.out");
    f>>a>>b;

    while ( a != b )
    {
        if ( a > b )
        {
            a = a - b;
        }
        else
        {
            b = b - a;
        }
    }
    f.close();

    if ( a != b )
    {
        g<<0;
    }
    else
    {
        g<<a;
    }
    g.close();
    return 0;
}