#include<iostream>
#include<algorithm>
#include<vector>
#include<functional>
#include<string>
#include<cmath>
#include<map>
#include<set>
#include<queue>
#include<stack>
#include<cstdio>
#include<numeric>
using namespace std;
using ll = long long;
using ld = long double;

ld p, q;
ld f(ld x) { return pow(x, 2) - q * x * log2l(x) - p; }
ld g(ld x) { return 2 * x - q * (log2l(x) - logl(2)); }

int main(){
  cin >> p >> q;
  const double eps = 1e-08;
  const int limit = 5000000;
  ld x, dx;
  ld a, b, c;
  a = 1;
  b = 1001001001001001001.0;
  while(fabs(a - b) > eps){
    c = (a + b) / 2;
    if(f(c) == 0){
      break;
    } 
    if(f(a) * f(c) < 0){
      b = c;
    }
    if(f(a) * f(c) > 0){
      a = c;
    }
  }
  printf("%.10Lf\n", c);
  return 0;
}