#include <bits/stdc++.h>
using namespace std;
int main(){
	int M,N,r=1;
	cin>>N>>M;
	while (r) 
	{r=M%N;
	M=N;
	N=r;
	}
	cout<<M;
	return 0;
	}

/**************************************************************
	Problem: 1088
	User: ljl2
	Language: C++
	Result: Accepted
	Time:8 ms
	Memory:2072 kb
****************************************************************/