#include<stdio.h>
long a,b;
long euclid(long a,long b){
                if(b==0) return a;
                  else return euclid(b,a%b);
                     }
int main()
{
 freopen("euclid2.in","r",stdin);
 freopen("euclid2.out","w",stdout);
 scanf("%ld %ld",&a,&b);
 a=euclid(a,b);
 printf("%ld",a);
 fclose(stdout);
 return 0;
}