#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: Compile Error
****************************************************************/