#include <fstream>

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

    g<<a;
   else
    g<<"0";
    return 0;
}