#include <bits/stdc++.h>
 
using namespace std;

double dp[1000001][1<<6];
vector <int> p[1<<6];
int main(void)
{
    cin.tie(0);
    ios::sync_with_stdio(false);

    int n;

    cin >> n;

    for(int i=0;i<(1<<6);i++)
    {
        int bcnt = 0;
        for(int j=0;j<6;j++)
        {
            if((i&(1<<j)))
            {
                bcnt++;
            }
            else
            {
                p[i].push_back(j);
            }
        }
    }
    dp[0][0] = 1;

    for(int i=0;i<n;i++)
    {
        for(int j=0;j<(1<<6);j++)
        {
            if(dp[i][j]<=0) continue;
            int cnt = p[j].size();
            dp[i+1][j] += ((dp[i][j]*cnt/6));
            for(auto k : p[j])
            {
                int bitmask = (j | (1<<k));
                dp[i+1][bitmask] += (dp[i][j]/6);
            }
        }
    }

    cout << fixed;
    cout.precision(16);

    cout << dp[n][63] << '\n';

    return 0;
}