#include<bits/stdc++.h>
using namespace std;
int main()
{
int m,n,r;
r=1;
cin>>m>>n;
while(r){
r=m%n;
m=n;
n=r;
}
cout<<m;
return 0;
}
/**************************************************************
Problem: 1088
User: fuyijun
Language: C++
Result: Accepted
Time:6 ms
Memory:2072 kb
****************************************************************/