#include <iostream>
#include <iomanip>
using namespace std;

int main() {
 
 
    int prime[] = {2,3,5,7,11,13};
    int mix[] = {4,6,8,9,10,12};
    int k;
    cin >> k;
    double ans = 0;
    double c = 0;
    for(int a:prime) {
        for(int b:mix) {
            if(a*b == k)c++;
        }
    }
    ans = c / 36;
    cout << setprecision(12) << ans;
  
}