#include<bits/stdc++.h>
using namespace std;

int main(){
	long long a,b,t;
	cin>>a>>b;
	while(a % b != 0){
		t = a % b;
		a = b;
		b = t;
	} 
	cout<<b<<endl;
	
	 
    return 0;
}

/**************************************************************
	Problem: 1335
	User: admin
	Language: C++
	Result: Accepted
	Time:8 ms
	Memory:2072 kb
****************************************************************/