#include<bits/stdc++.h>
using namespace std;
int main(){
    long p,q;
    cin >> p >> q;
    double n = 1.0e12;
    double eps = n/2.0;
    while(eps > 1.0e-6){
        double takahashi = n*n;
        double hikuhashi = 0.0;
        hikuhashi += (double)p;
        hikuhashi += (double)q * n * log2l(n);
        if(takahashi > hikuhashi)n -= eps;
        else n += eps;

        eps /= 2;
    }
    printf("%.20lf",n);
    
}