#include <iostream>
#include <cstdio>
#include <string>
#include <algorithm>
#include <utility>
#include <cmath>
#include <vector>
#include <queue>
#include <set>
#include <map>
#include <functional>
using namespace std;
typedef long long ll;
typedef vector<ll> vl;
typedef vector<vector<ll>> vvl;
typedef pair<ll, ll> P;
typedef vector<vector<P>> vvP;
#define rep(i, n) for(ll i = 0; i < n; i++)
#define exrep(i, a, b) for(ll i = a; i <= b; i++)
#define out(x) cout << x << endl
#define exout(x) printf("%.20f\n", x)
#define chmax(x, y) x = max(x, y)
#define chmin(x, y) x = min(x, y)
#define all(a) a.begin(), a.end()
#define rall(a) a.rbegin(), a.rend()
#define pb push_back
#define re0 return 0
const ll mod = 1000000007;
const ll INF = 1e16;
const ll MAX_N = 100010;

ll v1[6] = {2, 3, 5, 7, 11, 13};
ll v2[6] = {4, 6, 8, 9, 10, 12};

int main() {
    ll k;
    cin >> k;

    ll cnt = 0;
    rep(i, 6) {
        rep(j, 6) {
            if(v1[i]*v2[j] == k) {
                cnt++;
            }
        }
    }

    exout((double)cnt/36.0);
    re0;
}