using System;
using static System.Console;
using System.Linq;
using System.Collections.Generic;
using System.Globalization;

class Program
{
    static int NN => int.Parse(ReadLine());
    static int[] NList => ReadLine().Split().Select(int.Parse).ToArray();
    static int[][] NArr(long n) => Enumerable.Repeat(0, (int)n).Select(_ => NList).ToArray();
    public static void Main()
    {
        Solve();
    }
    static void Solve()
    {
        var c = NList;
        var (p, q) = (c[0], c[1]);
        var ok = 1.0;
        var ng = q * 35.0;
        while (ng - ok > 0.0000001)
        {
            var mid = (ok + ng) / 2;
            if (mid < p / mid + q * Math.Log2(mid)) ok = mid;
            else ng = mid;
        }
        WriteLine(ok);
    }
}