#include <fstream>

using namespace std;
ifstream f("cmmdc.in");
ofstream g("cmmdc.out");
int a,b,c;
int main()
{
    f>>a>>b;
    while (b!=0)
    {
        c=b;
        b=a%b;
        a=c;
    }
    if (a==1)
        a=0;
    g << a;
    return 0;
}