#include <cstdio>

int main(void) {
	freopen("euclid2.in", "rt", stdin);
	freopen("euclid2.out", "wt", stdout);

	int a, b, r;

	scanf(" %d %d", &a, &b);

	while (b) {
		r = a % b;
		a = b;
		b = r;
	}

	printf("%d\n", a);

	return 0;
}