#include <iostream>
#include <algorithm>
#include <string>
#include <vector>
#include <map>
#include <set>
#include <stdio.h>
#include <cstring>
#include <queue>
#include <stack>
#include <functional>
#include <math.h>
#include <iomanip>
using namespace std;
#define Would
#define you
const int INF = 999999999;
const int MOD = 1e9 + 7;

int prime[] = { 2,3,5,7,11,13 }, gosei[] = { 4,6,8,9,10,12 }, n, ans;
int main() {
	cin >> n;
	for (int i = 0; i < 6; ++i) {
		for (int j = 0; j < 6; ++j) {
			if (prime[i] * gosei[j] == n) { ++ans; }
		}
	}
	cout << setprecision(50) << (double)ans / 36 << endl;
}