a,b=map(int,input().split()) def f(a,b): if a%b: return f(b,a%b) else: return b print(f(a,b))

#include<iostream> using namespace std; long long f(long n,long m){ if(n%m==0) return m; return f(m,n%m); } int main(){ long n,m; cin>>n>>m; cout<<f(n,m); return 0; }

#include<bits/stdc++.h> using namespace std; int main(){ int a,b; cin>>a>>b; cout<<__gcd(a,b); }