#include <bits/stdc++.h>
#define rep(i,n) for(int i = 0; i < (n); ++i)
#define srep(i,s,t) for (int i = s; i < t; ++i)
#define drep(i,n) for(int i = (n)-1; i >= 0; --i)
using namespace std;
typedef long long int ll;
typedef pair<int,int> P;
#define yn {puts("YES");}else{puts("NO");}
#define MAX_N 200005

int main() {
    double p, q;
    cin >> p >> q;
    double l = 1, r = 1e15;
    int loop = 0;
    while(loop < 1000){
        loop++;
        double m = (l + r) / 2;
        if(m*m <= p+q*m*log2(m)) l = m;
        else r = m;
    }
    cout << fixed << setprecision(10) << l << endl;
    return 0;
}