#include<stdio.h>
long long m,n;
long long f(long long a,long long b)
{
	if(a%b==0)	return b;
	return f(b,a%b);
}
int main()
{
	scanf("%lld %lld",&m,&n);
	printf("%lld",f(m,n));
	return 0;
} 
/**************************************************************
	Problem: 1335
	User: admin
	Language: C
	Result: Accepted
	Time:10 ms
	Memory:1144 kb
****************************************************************/