#include <bits/stdc++.h>
using namespace std;
#define rep(i, n) for (int i = 0; i < (int)(n); i++)
#define all(x) (x).begin(), (x).end()
#define ll long long
#define ld long double
#define INF 1000000000000000000
typedef pair<ll, ll> pll;
typedef pair<int, int> pint;

ld P, Q;
bool isOK(ld key) { return P + Q * key * log2(key) >= key * key; }

int main() {
    cin.tie(0);
    ios::sync_with_stdio(false);

    cin >> P >> Q;
    ld ok = 0.0, ng = 1000000000000000.0;
    while (abs(ok - ng) > 1e-8) {
        ld mid = (ok + ng) / 2;
        if (isOK(mid))
            ok = mid;
        else
            ng = mid;
    }

    cout << fixed << setprecision(10) << ok << endl;
}