#include <bits/stdc++.h>
using namespace std;
using ll = long long;
int main() {
	vector<int> d1 = {2,3,5,7,11,13};
	vector<int> d2 = {4,6,8,9,10,12};
	int n,a=0;
	cin>>n;
	for(int i=0;i<6;i++){
		for(int j=0;j<6;j++){
			if(d1[i]*d2[j]==n)a++;
		}
	}
	cout<<fixed<<(a+0.0)/36;
}