#include "bits/stdc++.h"
using namespace std;
typedef long long ll;
ll N;

ll mod = 1e9 + 7;

ll gcd(ll a, ll b){return b?gcd(b,a%b):a;}

int main(){

    ll A, B;
    cin >> A >> B;

    if(A < B){
        swap(A, B);
    }

    cout << gcd(A, B) << endl;


}