#include <iostream>
#include <vector>
#include <algorithm>
#include <string>
#include <sstream>
#include <cstring>
#include <cstdio>
#include <cstdlib>
#include <cmath>
#include <queue>
#include <stack>
#include <map>
#include <set>
#include <numeric>
#include <cctype>
#include <tuple>
#include <array>
#include <climits>
#include <bitset>
#include <cassert>

#ifdef _MSC_VER
#include <agents.h>
#endif

#define FOR(i, a, b) for(int i = (a); i < (int)(b); ++i)
#define rep(i, n) FOR(i, 0, n)
#define ALL(v) v.begin(), v.end()
#define REV(v) v.rbegin(), v.rend()
#define MEMSET(v, s) memset(v, s, sizeof(v))
#define UNIQUE(v) (v).erase(unique(ALL(v)), (v).end())
#define MP make_pair
#define MT make_tuple

using namespace std;

typedef long long ll;
typedef long double ld;
typedef pair<int, int> P;

const int N = 1e6 + 10;
double dp[N];

int main(){
	cin.tie(0);
	ios::sync_with_stdio(false);
	cout.setf(ios::fixed);
	cout.precision(20);

	int n;
	double p;
	cin >> n >> p;	

	rep(i, n + 1) dp[i] = 1;
	for (int i = 2; i <= n; ++i){
		if (dp[i] != 1) continue;
		for (int j = i * 2; j <= n; j += i){
			int cnt = 0, x = j/i;
			while (x%i == 0) x /= i, ++cnt;
			if (!cnt) ++cnt;
			dp[j] *= pow(p, cnt);
		}
	}
	cout << accumulate(dp + 2, dp + n + 1, 0.0) << endl;
}