#include <iostream>

#define rep(i, n) for(int i = 0; i < (n); i++)
#define f(i, n, m) for(int i = n; i < (m); i++)

using namespace std;
float dp[1 << 6][100005];

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

	dp[0][0] = 1;

	f(i, 1, n + 1) {
		rep(j, 1 << 6) {
			rep(k, 6) {
				int m = 1 << k;
				dp[i][j | m] += dp[i - 1][j] / 6;
			}
		}
	}

	cout << dp[n][(1 << 6)-1] << endl;

	return 0;
}