#include <bits/stdc++.h>

#define show(x) cerr << #x << " = " << x << endl

using namespace std;
using ll = long long;

template <typename T>
ostream& operator<<(ostream& os, const vector<T>& v)
{
    os << "sz:" << v.size() << "\n[";
    for (const auto& p : v) {
        os << p << ",";
    }
    os << "]\n";
    return os;
}

template <typename S, typename T>
ostream& operator<<(ostream& os, const pair<S, T>& p)
{
    os << "(" << p.first << "," << p.second
       << ")";
    return os;
}


constexpr ll MOD = (ll)1e9 + 7LL;

template <typename T>
constexpr T INF = numeric_limits<T>::max() / 64;

int main()
{
    cin.tie(0);
    ios::sync_with_stdio(false);
    constexpr int p[6] = {2, 3, 5, 7, 11, 13};
    constexpr int c[6] = {4, 6, 8, 9, 10, 12};

    vector<int> num(157, 0);
    for (int i = 0; i < 6; i++) {
        for (int j = 0; j < 6; j++) {
            num[p[i] * c[j]]++;
        }
    }
    int k;
    cin >> k;
if(k > 156){
cout << 0 << endl;
return 0;
}

    cout << fixed << setprecision(15) << (long double)(num[k]) / 36 << endl;

    return 0;
}