#include<iostream>
#include<algorithm>
#include<string>
#include<cstdlib>
#include<map>
#include<iomanip>
#include<sstream>
using namespace std;


int main() {
	long long int n,sum=0,v;
	long double sai[1000050][7] = {};
	cin >> n;
	if (n > 10000) {
		cout << "0.99999999999999"<<endl;
	}
	sai[0][0] = 1;
	for (int i = 1; i <= n; i++) {
		for (int j = 0; j <= 5; j++) {
			sai[i][j] += sai[i - 1][j] * (j) / 6;
			sai[i][j + 1] += sai[i - 1][j] * (6 - j) / 6;
		}
		sai[i][6] += sai[i - 1][6];
	}
	cout << setprecision(15) << sai[n][6]<<endl;
}