#include <bits/stdc++.h>
using namespace std;

int main() {
    double P, Q;
    cin >> P >> Q;

    double ok = 1.0, ng = 1e12;
    while (ng - ok > 1e-5) {
        double N = ok + (ng - ok) / 2;
        if (N * N <= Q * log2(N) * N + P) {
            ok = N;
        } else {
            ng = N;
        }
    }

    cout << ok << endl;

    return 0;
}