#include<bits/stdc++.h>
using namespace std;
using Int = long long;
template<typename T1,typename T2> inline void chmin(T1 &a,T2 b){if(a>b) a=b;}
template<typename T1,typename T2> inline void chmax(T1 &a,T2 b){if(a<b) a=b;}

struct Precision{
  Precision(){
    cout<<fixed<<setprecision(12);
  }
}precision_beet;

//INSERT ABOVE HERE
signed main(){
  using D = long double;
  int n;
  cin>>n;
  
  D ans=0;
  const int t=6;
  int s=1<<t;
  for(int b=0;b<s;b++){
    D cnt=0,res=1;
    for(int i=0;i<t;i++)
      if((b>>i)&1) cnt+=1.0,res*=-1; 
    ans+=res*pow(cnt/t,n);
  }
  
  cout<<ans<<endl;
  return 0;
}