#include <iostream>
#include <vector>
#include <algorithm>
#include <queue>
#include <cmath>
#include <iomanip>

using namespace std; using ll=long long; const int INF=1e9;
typedef pair<int,int> P;

int main() {
  long double p,q; cin>>p>>q;
  long double ok=0, ng=1e12;

  for(int i=0;i<100;i++) {
    long double n = (ok + ng) / 2.0;
    //cout << n << " " << p + q * log2(n) << endl;
    if (n * n <= p + q * n * log2(n)) ok = n;
    else ng = n;
  }

  cout<<fixed<<setprecision(20)<<ok<<endl;
}