#include <charconv>
#include <cstdio>
#include <vector>

using namespace std;
using ll = long long;

int main() {
    ll n;
    scanf("%lld", &n);
    const int c64 = 1 << 6;
    vector<vector<double>> dp(2, vector<double>(c64, 0.0));
    dp[0][0] = 1.0;
    for (ll i = 0; i < n; i++) {
        for (int k = 0; k < c64; k++) {
            dp[(i + 1) % 2][k] = 0.0;
        }
        for (int flag = 0; flag < c64; flag++) {
            double v = dp[i % 2][flag];
            for (int dice = 0; dice < 6; dice++) {
                dp[(i + 1) % 2][flag | (1 << dice)] += v / 6.0;
            }
        }
    }
    char buf[64];
    *to_chars(buf, buf + sizeof buf, dp[n % 2][c64 - 1]).ptr = '\0';
    printf("%s\n", buf);
}