#define _USE_MATH_DEFINES
#include <bits/stdc++.h>
using namespace std;
signed main() {
	ios::sync_with_stdio(false);
	cin.tie(0);
	int n;
	cin >> n;
	double p;
	cin >> p;
	vector<int> a(n + 1);
	for (int i = 2; i <= n; i++) {
		int x = i;
		vector<int> b;
		for (int j = 2; j * j <= x; j++) {
			int c = 0;
			while (x % j == 0) {
				c++;
				x /= j;
			}
			if (c != 0) b.push_back(c);
		}
		if (x != 1) b.push_back(1);
		int cnt = 1;
		for (auto &j : b) {
			cnt *= j + 1;
		}
		a[i] = cnt;
	}
	double ans = 0;
	for (int i = 2; i <= n; i++) {
		ans += pow(1.0 - p, a[i] - 2);
	}
	cout << setprecision(20) << fixed << ans << '\n';
	return 0;
}