#include <bits/stdc++.h>
using namespace std;
int main() {
  long double p, q;
  cin >> p >> q;
  long double ok = 5e10;
  long double ng = 0;
  for (int i = 0; i < 1000000; i++) {
    long double n = (ok + ng) / 2.0;
    if (n * n >= p + q * n * log2(n)) {
      ok = n;
    } else {
      ng = n;
    }
  }
  cout << fixed << setprecision(15);
  cout << ok << endl;
  return 0;
}