#include <bits/stdc++.h>
using namespace std;

int main(){
    ios_base::sync_with_stdio(false);
    cin.tie(nullptr);

    int N; cin >> N;
    double p; cin >> p; p = 1-p;
    vector<double> P(N+1,1);
    P.at(2) = 1;
    double answer = 0;
    for(int i=2; i<=N; i++){
        answer += P.at(i);
        for(int k=i+i; k<=N; k+=i) P.at(k) *= p;
    }
    cout << fixed << setprecision(20) << answer << endl;
}