#include <cstdio>
#include <iostream>
#include <string>
#include <sstream>
#include <stack>
#include <algorithm>
#include <cmath>
#include <queue>
#include <map>
#include <set>
#include <cstdlib>
#include <bitset>
#include <tuple>
#include <assert.h>
#include <deque>
#include <bitset>
#include <iomanip>
#include <limits>
#include <chrono>
#include <random>
#include <array>
#include <unordered_map>
#include <functional>
#include <complex>

template<class T> inline bool chmax(T& a, T b) { if (a < b) { a = b; return 1; } return 0; }
template<class T> inline bool chmin(T& a, T b) { if (a > b) { a = b; return 1; } return 0; }

const long long MAX = 5100000;
const long long INF = 1LL << 60;
//const long long mod = 1000000007LL;
//const long long mod = 998244353LL;

using namespace std;
typedef unsigned long long ull;
typedef long long ll;

long double dp[1000500][8];
int main()
{
	/*
	cin.tie(nullptr);
	ios::sync_with_stdio(false);
	*/

	int n; scanf("%d", &n);
	dp[0][0] = 1;
	chmin(n, 1000);
	for (ll i = 0; i < n; i++) {
		for (ll j = 0; j <= 6; j++) {
			dp[i + 1][j + 1] += dp[i][j] * (6 - j) / 6.0;
			dp[i + 1][j] += dp[i][j] * j / 6.0;
		}
	}

	cout << fixed << setprecision(12) << dp[n][6] << endl;
	return 0;
}