#include <stdio.h>
int a,b,cmmdc;
int main()
{
freopen("euclid2.in", "r", stdin);
freopen("euclid2.out", "w", stdout);
scanf("%d %d", &a, &b);
cmmdc=b;
if(b==0 ) cmmdc=a; 
else while(a%b!=0){cmmdc=a%b; a=b; b=cmmdc;}
  
  printf("%d\n", cmmdc);
  return 0;
}