#include<stdio.h>

long cmmdc(long a, long b)
{
	if (b)
		return cmmdc(b, a%b);
	 return a;
}

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