#include <bits/stdc++.h>
using namespace std;
template<class T> inline bool chmax(T& a, T b) { if (a < b) { a = b; return true; } return false; }
template<class T> inline bool chmin(T& a, T b) { if (a > b) { a = b; return true; } return false; }
using ll = long long;
using P = pair<ll, ll>;
const long double PI = acos(-1.0L);
ll GCD(ll a, ll b) { return b?GCD(b, a%b):a; }
ll LCM(ll a, ll b) { return a/GCD(a, b)*b; }


int main() {
    int n; cin >> n;
    long double ans = 0.0L;
    ans = 6.0L*powl(5.0L/6.0L, n) - 15.0L*powl(4.0L/6.0L, n) + 20.0L*powl(3.0L/6.0L, n) - 15.0L*powl(2.0L/6.0L, n) + 6.0L*powl(1.0L/6.0L, n);
    cout << setprecision(14) << 1.0L-ans << endl;
}