#include <stdio.h>

int a, b;

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