/* Author:zeke pass System Test! GET AC!! */ #include <iostream> #include <queue> #include <vector> #include <iostream> #include <vector> #include <string> #include <cassert> #include <algorithm> #include <functional> #include <cmath> #include <queue> #include <set> #include <stack> #include <deque> #include <map> #include <iomanip> #include <utility> #include <stack> #include <bitset> using ll = long long; using ld = long double; using namespace std; #define rep(i, n) for (int i = 0; i < (int)(n); i++) #define all(x) (x).begin(), (x).end() #define rep3(var, min, max) for (ll(var) = (min); (var) < (max); ++(var)) #define repi3(var, min, max) for (ll(var) = (max)-1; (var) + 1 > (min); --(var)) #define Mp(a, b) make_pair((a), (b)) #define F first #define S second #define Icin(s) \ ll(s); \ cin >> (s); #define Scin(s) \ ll(s); \ cin >> (s); template <class T> bool chmax(T &a, const T &b) { if (a < b) { a = b; return 1; } return 0; } template <class T> bool chmin(T &a, const T &b) { if (b < a) { a = b; return 1; } return 0; } typedef pair<ll, ll> P; typedef vector<ll> V; typedef vector<V> VV; typedef vector<P> VP; ll mod = 1e9 + 7; ll MOD = 1e9 + 7; ll INF = 1e18; int main() { cin.tie(0); ios::sync_with_stdio(false); vector<vector<float>> dp(1e6 + 1, vector<float>(7)); dp[0][0] = 1.0; rep3(i, 1, 1e6 + 1) { for (ld j = 1; j < 7; j++) { ld k = (6 - (j - 1)) / 6; ld k2=j/6; dp[i][j] += dp[i - 1][j]*k2; dp[i][j] += dp[i - 1][j - 1] * k; } } ll n; cin >> n; cout<<setprecision(10)<< dp[n][6] << endl; // cout<<"hello"<<endl; }