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

double dp[1000001][1<<6];

int main(void)
{
    cin.tie(0);
    ios::sync_with_stdio(false);

    int n;

    cin >> n;

    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;
            for(int k=0;k<6;k++)
            {
                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;
}