#include <iostream>
#include <string>
#include <vector>
#include <queue>
#include <deque>
#include <algorithm>
#include <set>
#include <map>
#include <bitset>
#include <cmath>
#include <functional>
#include <iomanip>
#define vll vector<ll>
#define vvvl vector<vvl>
#define vvl vector<vector<ll>>
#define VV(a, b, c, d) vector<vector<d>>(a, vector<d>(b, c))
#define VVV(a, b, c, d) vector<vvl>(a, vvl(b, vll (c, d)));
#define re(c, b) for(ll c=0;c<b;c++)
#define all(obj) (obj).begin(), (obj).end()
typedef long long int ll;
typedef long double ld;
using namespace std;


int main(int argc, char const *argv[]) {
  ll k;std::cin >> k;
  vll x(1000, 0);
  int a[6] = {2, 3, 5, 7, 11, 13};
  int b[6] = {4, 6, 8, 9, 10, 12};

  for(int i=0;i<6;i++){
    for(int j=0;j<6;j++){
      x[a[i]*b[j]]++;
    }
  }
  std::cout << (x[k]==0?0:(ld)(x[k])/36.0) << '\n';

  return 0;
}