#include <algorithm>
#include <iostream>
#include <iomanip>
#include <map>
#include <numeric>
#include <set>
#include <sstream>
#include <string>
#include <vector>
#include <cmath>
#include <unordered_map>
#include <climits>
using namespace std;

#define REPI(i,a,b) for (ll i=(a);i<(b);i++)
#define REP(i,n) REPI(i,0,n)

typedef long long int ll;

int SURP = 1000000007;

int ceil(int a,int b){
	return (a+b-1)/b;
}

ll gcd(ll a,ll b){
	ll p;

	if (b > a){
		p = a;
		a = b;
		b = p;
	}

	while(b != 0){
		p = a % b;
		a = b;
		b = p;
	}
	return a;
}

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

	ll s1[] = {2,3,5,7,11,13};
	ll s2[] = {4,6,8,9,10,12};

	ll c = 0;

	REP(i,6){
		REP(j,6){
			if(s1[i]*s2[j] == K) c++;
		}
	}

	float ret = (float)c/36.0;
	cout << setprecision(15) << ret << endl;

	return 0;
}