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

using namespace std;

int main() {
	int n;
	double p;

	cin >> n >> p;

	vector<bool> isPrime(n + 1, true);
	isPrime[0] = isPrime[1] = false;

	for (int i = 2; i * i <= n; i++) {
		if (isPrime[i]) {
			for (int j = i * 2; j <= n; j += i) {
				isPrime[j] = false;
			}
		}
	}
	vector<int> primes(n, 0);
	int n_p = 0;
	for (int i = 0; i < n; i++) {
		if (isPrime[i]) {
			primes[n_p] = i;
			n_p++;
		}
	}

	vector<int> divisor(n + 1, 0);
	divisor[1] = 1;
	int div, tmp, idx;
	for (int i = 2; i <= n; i++) {
		if (isPrime[i]) {
			divisor[i] = 2;
		} else {
			for (int j = 0; j < n_p; j++) {
				if (i % primes[j] == 0) {
					tmp = i;
					while (tmp % primes[j] == 0) {
						tmp /= primes[j];
					}
					divisor[i] = divisor[i / primes[j]] + divisor[tmp];
					break;
				}
			}
		}
	}

	double ans = 0.0;
	for (int i = 2; i <= n; i++) {
		ans += pow(1.0 - p, divisor[i] - 2);
	}
	printf("%.6f\n", ans);
	return 0;
}