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 = 0; var prime = new bool[N + 1]; var pow = new double[10000]; var cnt = new int[N + 1]; pow[1] = (1 - P); for (int i = 2; i < 10000; i++) { pow[i] = pow[i - 1] * (1 - P); } for (int i = 2; i <= N; i++) { int idx = 2; if (cnt[i] == 0) ans++; while (i * idx <= N) { cnt[i * idx]++; idx++; } } for (int i = 2; i <= N; i++) { if (cnt[i] > 0) { ans += pow[cnt[i]]; } } Console.WriteLine(ans); } } }