#include <bits/stdc++.h> using namespace std; typedef long long ll; typedef pair<int,int> P; typedef pair<int,P> P1; typedef pair<P,P> P2; #define pu push #define pb push_back #define mp make_pair #define eps 1e-7 #define INF 1000000000 #define mod 1000000007 #define fi first #define sc second #define rep(i,x) for(int i=0;i<x;i++) #define repn(i,x) for(int i=1;i<=x;i++) #define SORT(x) sort(x.begin(),x.end()) #define ERASE(x) x.erase(unique(x.begin(),x.end()),x.end()) #define POSL(x,v) (lower_bound(x.begin(),x.end(),v)-x.begin()) #define POSU(x,v) (upper_bound(x.begin(),x.end(),v)-x.begin()) double hoge[7],ret; int main(){int n;cin>>n; for(int i=1;i<=5;i++){ //6Ci * (i/6)^n double x = 72.0; for(int j=1;j<=i;j++) x/=(double)j; for(int j=1;j<=6-i;j++) x/=(double)j; double f = (double)i/6.0; for(int j=0;j<n;j++) x*=f; if(i%2==1) ret-=x; else ret+=x; } printf("%.12f\n",ret*10.0+1.0); }