#include <bits/stdc++.h>
using namespace std;

#define BIT(x) (1ull << (x))
#define FOR(i, a, b) for (int i = (int)(a); i < (int)(b); i++)
#define REP(i, n) FOR(i, 0, n)
#define RFOR(i, a, b) for (int i = (int)(a) - 1; i >= (int)(b); i--)
#define RREP(i, n) RFOR(i, n, 0)
#define EACH(i, v) for (__typeof((v).begin()) i = (v).begin(); i != (v).end(); ++i)
#define ALL(v) (v).begin(), (v).end()
#define RALL(v) (v).rbegin(), (v).rend()
#define UNIQ(v) do {sort(ALL(v)); (v).erase(unique(ALL(v)), (v).end());} while (0)
#define PB push_back
#define POP pop_back
#define MP make_pair
#define SIZE(v) ((int)(v).size())
#define DEBUG(x) cout << #x << " = " << x << endl



int main()
{
	int T[] = {2, 3, 5, 7, 11, 13};
	int U[] = {4, 6, 8, 9, 10, 12};
	int k;
	scanf("%d", &k);
	int cnt = 0;
	for (int i : T){
		for (int j : U){
			if (i * j == k) cnt++;
		}
	}
	printf("%.20f\n", (double)cnt / 36.0);
}