#include <fstream>

using namespace std;

ifstream fin("cmmdc.in");
ofstream fout("cmmdc.out");

int main() {
 int a, b;
 fin >> a >> b;
 while (a != b) {
  if (a > b)
   a -= b;
  else
   b -= a;
 }
 if (a > 1)
  fout << a;
 else
  fout << 0;
}