#include <stdio.h>
long a,b,c;

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