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

#define ll long long
#define rep(i, n) for (int i = 0; i < (n); i++)
#define P pair<int, int>

int main() {
  double p, q;
  cin >> p >> q;

  double ac = 1, wa = 1e13;
  rep(i,100) {
    double wj = (ac+wa)/2;
    if (wj*wj <= p+q*wj*log2(wj)) ac = wj;
    else wa = wj;
  }
  cout << fixed << setprecision(15) << ac << endl;


}