#include <bits/stdc++.h>

using namespace std;

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

	long double P, Q;

	cin >> P >> Q;

	long double lo = 0;
	long double hi = 1e18;
	long double res = 0;

	for (int i = 0; i < 200; i++)
	{
		long double mid = (lo + hi) / 2;
		long double val = Q * mid * log2(mid) + P;
		long double val2 = mid * mid;
		if (val2 <= val)
		{
			res = max(res, mid);
			lo = mid;
		}
		else
		{
			hi = mid;
		}
	}

	cout << fixed;
	cout.precision(9);

	cout << res << '\n';

	return 0;
}