#include <iostream>
#include <algorithm>
#include <vector>
#include <cmath>
#include <utility>
#include <iomanip>

std::vector<std::pair<int, int>> PrimeFact(int n){
	std::vector<std::pair<int, int>> result;
	double sqrtn = std::sqrt(n);
	for(int i=2; i<=sqrtn; ++i){
		int divCount = 0;
		if(n%i == 0){
			do{
				++divCount;
				n/=i;
			}while(n%i == 0);
		    result.push_back(std::make_pair(i, divCount));
		}
	}
    if(n!=1){
        result.push_back(std::make_pair(n, 1));
    }
	return result;
}

int main(){
    std::ios::sync_with_stdio(false);
    std::cin.tie(0);
    
    int n;
    double p;
    std::cin >> n >> p;
    p=1.0-p;
    double e = 0.0;
    for(int i=2; i<=n; ++i){
        auto pp = PrimeFact(i);
        int divNum = 1;
        for(auto it : pp){
            divNum *= it.second+1;
        }
        e += std::pow(p, divNum-2);
    }
    std::cout << std::fixed << std::setprecision(6) << e << "\n";
    return 0;
}