#include <bits/stdc++.h>
using namespace std;
#define rep(i,n) for(int i = 0; i < (n);i++)
#define sz(x) int(x.size())
typedef long long ll;
typedef long double ld;
typedef pair<int,int> P;

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

  ld l = 0, r = 1e15;
  auto ok = [&](ld x){
    ld a = x * x;
    ld b = p + q * x * log2l(x);
    return (a <= b);
  };
  for (int i = 0; i < 100000; i++) {
    ld m = (r + l) / 2.0;
    if (ok(m)) l = m;
    else r = m;
  }
  printf("%.12Lf\n", l);
  return 0;
}