#include <bits/stdc++.h>
using namespace std;
const long long mod = 1e9 + 7;
const long double pi = acos(-1.0); 
typedef long long ll;
 
int main() {
	cin.tie(0);
	ios::sync_with_stdio(false);

	double p, q;
	cin >> p >> q;
	double right, left, mid;
	right = LONG_MAX;
	left = 1.0;
	while(right - left > 0.00001) {
		mid = (right + left) / 2.0;
		long double i =  p + mid * q * log2(mid);
		if(i >= mid * mid) {
			left = mid;
		}else {
			right = mid;
		}
	}
	cout << fixed << setprecision(6) << left << endl;
}