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

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

    double l = 1, r = 1e18;
    while(r - l > 1e-6) {
        double m = (l + r) / 2;
        if(m * m + 1e-8 < P + Q * m * log2(m)) l = m;
        else r = m;
    }
    cout << fixed << setprecision(10) << l << '\n';
}