#include <bits/stdc++.h>
#define EPS 1e-9
#define INF 1070000000LL
#define MOD 1000000007LL
#define fir first
#define foreach(it,X) for(auto it=(X).begin();it!=(X).end();it++)
#define numa(x,a) for(auto x: a)
#define ite iterator
#define mp make_pair
#define rep(i,n) rep2(i,0,n)
#define rep2(i,m,n) for(int i=m;i<(n);i++)
#define pb push_back
#define pf push_front
#define sec second
#define sz(x) ((int)(x).size())
#define ALL( c ) (c).begin(), (c).end()
#define gcd(a,b) __gcd(a,b)
#define mem(x,n) memset(x,n,sizeof(x))
#define endl "\n"
using namespace std;
template <int POS, class TUPLE> void deploy(std::ostream &os, const TUPLE &tuple){}
template <int POS, class TUPLE, class H, class ...Ts> void deploy(std::ostream &os, const TUPLE &t){ os << (POS == 0 ? "" : ", ") << get<POS>(t); deploy<POS + 1, TUPLE, Ts...>(os, t); }
template <class T,class U> std::ostream& operator<<(std::ostream &os, std::pair<T,U> &p){ os << "(" << p.first <<", " << p.second <<")";return os; }
template <class T> std::ostream& operator<<(std::ostream &os, std::vector<T> &v){ int remain = v.size(); os << "{"; for(auto e: v) os << e << (--remain == 0 ? "}" : ", "); return os; }
template <class T> std::ostream& operator<<(std::ostream &os, std::set<T> &v){ int remain = v.size(); os << "{"; for(auto e: v) os << e << (--remain == 0 ? "}" : ", "); return os; }
template <class T, class K> std::ostream& operator<<(std::ostream &os, std::map<T, K> &mp){ int remain = mp.size(); os << "{"; for(auto e: mp) os << "(" << e.first << " -> " << e.second << ")" << (--remain == 0 ? "}" : ", "); return os; }
#define DEBUG1(var0) { std::cerr << (#var0) << "=" << (var0) << endl; }
#define DEBUG2(var0, var1) { std::cerr << (#var0) << "=" << (var0) << ", ";DEBUG1(var1); }
#define DEBUG3(var0, var1, var2) { std::cerr << (#var0) << "=" << (var0) << ", ";DEBUG2(var1,var2); }
#define DEBUG4(var0, var1, var2, var3) { std::cerr << (#var0) << "=" << (var0) << ", ";DEBUG3(var1,var2,var3); }
using ll = long long;
#define f(card, i) (card & (1<<i))
/*
inline bool f(int card, int i){
  return (card & (1 << i));
}
*/
inline int calc(int card){
  int ret = 0;
  ret += f(card, 0) && f(card, 1) && f(card, 2) && f(card, 3) && f(card, 4);
  ret += f(card, 0) && f(card, 5) && f(card, 10) && f(card, 15) && f(card, 20);
  ret += f(card, 1) && f(card, 2) && f(card, 3) && f(card, 4) && f(card, 5);
  ret += f(card, 1) && f(card, 6) && f(card, 11) && f(card, 16) && f(card, 21);
  ret += f(card, 2) && f(card, 3) && f(card, 4) && f(card, 5) && f(card, 6);
  ret += f(card, 2) && f(card, 7) && f(card, 12) && f(card, 17) && f(card, 22);
  ret += f(card, 3) && f(card, 4) && f(card, 5) && f(card, 6) && f(card, 7);
  ret += f(card, 3) && f(card, 8) && f(card, 13) && f(card, 18) && f(card, 23);
  ret += f(card, 4) && f(card, 5) && f(card, 6) && f(card, 7) && f(card, 8);
  ret += f(card, 4) && f(card, 9) && f(card, 14) && f(card, 19) && f(card, 24);
  ret +=  f(card, 0) && f(card, 6) && f(card, 12) && f(card, 18) && f(card, 24);
  ret +=  f(card, 4) && f(card, 8) && f(card, 12) && f(card, 16) && f(card, 20);
  return ret;
}

inline double comb(int n, int r){
  if (n < r) {
    return 0;
  }
  double ret = 1;
  for (int i = 1; i <= r; i++, n--) {
    ret = ret * n / i;
  }
  return ret;
}


int sum[15][30];
double times[30];
int main()
{
  cin.tie(0);
  ios_base::sync_with_stdio(0);
  int N;
  cin >> N;
  for (int b = 1; b < (1<<25); b++) {
    if (__builtin_popcount(b) > N) {
      continue;
    }
    sum[calc(b)][__builtin_popcount(b)] += 1;
  }

  double ans = 0;
  double mom = 1.0 / comb(99,N);
  rep(j,26){
    times[j] = comb(74,N-j) * mom;
  }
  rep2(i,1,13){
    rep(j,26){
      if (sum[i][j]) {
        ans += i * sum[i][j] * times[j];
      }
    }
  }
  //1/99CN
  cout << fixed << setprecision(10) << ans << endl;
  return 0;
}