#include <iostream>

using namespace std;

int main() {
    ios_base::sync_with_stdio(false);
    cin.tie(NULL);

    int A, B;
    cin >> A >> B;

    for (int x = 1; ; ++x) {
        if (x % A == B % x) {
            cout << x << "\n";
            break;
        }
    }

    return 0;
}