#include <cstdio>
#include <iostream>
#include <string>
#include <sstream>
#include <stack>
#include <algorithm>
#include <cmath>
#include <queue>
#include <map>
#include <set>
#include <cstdlib>
#include <bitset>
#include <tuple>
#include <assert.h>
#include <deque>
#include <bitset>
#include <iomanip>
#include <limits>
#include <chrono>
#include <random>
#include <array>
#include <unordered_map>
#include <functional>
#include <complex>
#include <numeric>

template<class T> inline bool chmax(T& a, T b) { if (a < b) { a = b; return 1; } return 0; }
template<class T> inline bool chmin(T& a, T b) { if (a > b) { a = b; return 1; } return 0; }

constexpr long long MAX = 5100000;
constexpr long long INF = 1LL << 60;
constexpr int inf = 1 << 28;
//constexpr long long mod = 1000000007LL;
constexpr long long mod = 998244353LL;

using namespace std;
typedef unsigned long long ull;
typedef long long ll;

long double f(ll P, ll Q, long double x) {
	long double sa = -(x * x);
	sa += P + (long double)Q * x * log2(x);
	return sa;
}
int main()
{
	/*
	cin.tie(nullptr);
	ios::sync_with_stdio(false);
	*/
	long double left = 1.0;
	long double right = 1e11;
	ll P, Q; scanf("%lld %lld", &P, &Q);

	for (int _ = 0; _ < 1000; _++) {
		long double mid = (left + right) / 2.0;
		if (f(P, Q, mid) > -1e-10) left = mid;
		else right = mid;
	}
	cout << fixed << setprecision(12) << left << "\n";
	return 0;
}