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

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

    double ok = 1.0, ng = 1e12;
    for (int i = 0; i < 100; i++) {
        double N = (ok + ng) / 2;
        if (N * N <= Q * log2(N) * N + P) {
            ok = N;
        } else {
            ng = N;
        }
    }

    cout << ok << endl;

    return 0;
}