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

int main(){
    vector<int> prime = {2,3,5,7,11,13};
    vector<int> composite = {4,6,8,9,10,12};
    int k;
    cin >> k;
    double ans = 0;
    for (auto x: prime) for (auto y: composite) if (x * y == k) {
        ans++;
    }
    ans /= 36;
    printf("%.13f\n",ans);
    return 0;
}