using System;
using System.Collections;
using System.Collections.Generic;
using System.Linq;
using System.Numerics;
using System.Text;
//using static CompLib.CompLib;
//using DataStructure;

namespace atcoder
{

    class Program
    {
        const int intMax = 1000000000;
        const long longMax = 2000000000000000000;
        static void Main(string[] args)
        {
            var NP = Console.ReadLine().Trim().Split().Select(double.Parse).ToArray();
            int N = (int)NP[0];
            double P = NP[1];
            double ans = N - 1;
            var prime = new bool[N + 1];
            var pow = new double[100];
            var cnt = new int[N + 1];
            pow[1] = P;
            for (int i = 2; i < 100; i++)
            {
                pow[i] = pow[i - 1] * P;
            }
            for (int i = 2; i <= N; i++)
            {
                int idx = 2;
                while (i * idx <= N)
                {
                    cnt[i * idx]++;
                    idx++;
                }
            }
            for (int i = 2; i <= N; i++)
            {
                if (cnt[i] > 0)
                    ans -= (1 - pow[cnt[i]]);
            }
            Console.WriteLine(ans);
        }
    }
}