#include <bits/stdc++.h>
using namespace std;
long long a,b;
//chuongtrinhcon
long long gcd(long long a,long long b)
{
if (b==0) return(a);
return gcd(b,a%b);
}
//chuongtrinhchinh
int main()
{
freopen("songuyen.inp","r",stdin);
cin>>a>>b;
cout<<gcd(a,b);
return 0;
}