#include <cstdio>

int cmmdc ( int a, int b ) {
	if (b == 0) return a;
	return cmmdc(b,a%b);
}

int main() {
	freopen("euclid2.in","rt",stdin);
	freopen("euclid2.out","wt",stdout);
	int a = 0,b = 0;
	scanf("%d %d",&a,&b);
	printf("%d\n",cmmdc(a,b));
	return 0;
}