#include<deque>
#include<queue>
#include<vector>
#include<algorithm>
#include<iostream>
#include<set>
#include<cmath>
#include<tuple>
#include<string>
#include<chrono>
#include<functional>
#include<iterator>
#include<random>
#include<unordered_set>
#include<unordered_map>
#include<array>
#include<map>
#include<iomanip>
//<< setprecision(5)

using namespace std;
typedef long long int llint;
typedef long double lldo;
#define mp make_pair
#define mt make_tuple
#define pub push_back
#define puf push_front
#define pob pop_back
#define pof pop_front
#define fir first
#define sec second
#define res resize
#define ins insert
#define era erase
#define dme cout<<-1<<endl;return 0
const int mod=1000000007;
const int big=1e9;
const long double pai=3.141592653589793238462643383279502884197;
const long double eps=1e-7;

template <class T,class U>void mineq(T& a,U b){if(a>b){a=b;}}
template <class T,class U>void maxeq(T& a,U b){if(a<b){a=b;}}
llint gcd(llint a,llint b){if(a%b==0){return b;}else return gcd(b,a%b);}
llint lcm(llint a,llint b){return a/gcd(a,b)*b;}
int main(void){
	lldo dp[7]={0};
	dp[0]=1;
	int n,i;
	cin>>n;
	while(n--){
		lldo ddp[7]={0};
		for(i=0;i<6;i++){
			ddp[i]+=dp[i]*i/6;
			ddp[i+1]+=dp[i]*(6-i)/6;
		}
		ddp[6]+=dp[6];
		swap(dp,ddp);
	}
	cout<<setprecision(25)<<dp[6]<<endl;
}