/* -*- coding: utf-8 -*-
 *
 * 567.cc: No.567 コンプリート - yukicoder
 */

#include<cstdio>
#include<cstdlib>
#include<cstring>
#include<cmath>
#include<iostream>
#include<string>
#include<vector>
#include<map>
#include<set>
#include<stack>
#include<list>
#include<queue>
#include<deque>
#include<algorithm>
#include<numeric>
#include<utility>
#include<complex>
#include<functional>
 
using namespace std;

/* constant */

const int D = 6;
const int DBITS = 1 << D;

/* typedef */

/* global variables */

double dp[2][DBITS];

/* subroutines */

/* main */

int main() {
  int n;
  cin >> n;

  dp[0][0] = 1.0;
  int cur = 0, nxt = 1;

  for (int i = 0; i < n; i++) {
    fill(dp[nxt], dp[nxt] + DBITS, 0);
    for (int bits = 0; bits < DBITS; bits++)
      for (int d = 0, bd = 1; d < D; d++, bd <<= 1)
	dp[nxt][bits | bd] += dp[cur][bits] / D;
    cur ^= 1, nxt ^= 1;
  }

  printf("%.8lf\n", dp[cur][DBITS - 1]);
}