#include <iostream>
#include <fstream>

using namespace std;
ifstream f("euclid2.in");
ofstream g("euclid2.out");

int main()
{
    int a,b,n,t,i;


      f>>a>>b>>t;
      if (a*b==0)
      f<<a+b;
      else
      while (a!=b)
      {


     if(a>b)
     a=a-b;
     else
     b=b-a;
      }
    g<<a;
    f.close();
    g.close();

    return 0;
}