#include <bits/stdc++.h>
#define _GLIBCXX_DEBUG
using namespace std;
using ll = long long;


int main() {
    int A,B;
    cin >> A >> B;
    for (int i=1; i<1000000; i++){
        if (i%A == B%i){
            cout << i << endl;
            break;
        }
    }
}