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

#define FOR(i,l,r) for(int i = int(l);i < int(r);i++)
template<typename T> bool chmax(T& a,const T& b){ return a < b ? (a = b,true) : false; }
template<typename T> bool chmin(T& a,const T& b){ return b < a ? (a = b,true) : false; }
typedef long long ll;

int N;
const int MAX_N = 10000;
double dp [MAX_N + 1] [1 << 6];

int main()
{
	scanf("%d",&N);
	chmin(N,MAX_N);

	dp [0] [0] = 1.0;
	FOR(i,0,N) FOR(j,0,1 << 6){
		FOR(k,0,6){
			dp [i + 1] [j | (1 << k)] += dp [i] [j] / 6.0;
		}
	}
	printf("%.17f\n",dp [N] [(1 << 6) - 1]);

	return 0;
}