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

int main()
{
    ifstream in("cmmdc.in");
    ofstream out("cmmdc.out");
    int a,b,r;
    in>>a>>b;
    while(b!=0)
    {
        r=a%b;
        a=b;
        b=r;
    }
    if(a==1)
        out<<"0";
    else out<<a;
   return 0;
}