#include <stdio.h>

long gcd(long x,long y)
{
	long r;
	if(y>x){
		r=x;
		x=y;
		y=r;
	}
	while(y>0){
		r=x%y;
		x=y;
		y=r;
	}
	return x;
}

int main(void)
{
	long a,b;
	scanf("%ld%ld",&a,&b);
	printf("%ld",gcd(a+b,gcd(a,b)));
	return 0;
}