/*
  Copyright 2011 Marek "p2004a" Rusinowski
  Euclidean algorithm
*/
#include <cstdio>

int gcd(int a, int b) {
  return b ? gcd(b, a % b) : a;
}

int main() {
  int a, b;
  scanf("%d %d", &a, &b);
  printf("%d\n", gcd(a, b));
  return 0;
}