#include <iostream>
#include <vector>
#include <algorithm>
#include <cmath>
#include <iomanip>
#include <stack>
#include <algorithm>
#include <string>
#include <map>
#include <iterator>
#include <set>
#include <queue>
#include <bitset>
#include <cassert>

using namespace std;


int main() {
    int K;
    cin>>K;
    int cnt = 0;
    vector<int> xs = {2, 3, 5, 6, 11, 13};
    vector<int> ys = {4, 6, 8, 9, 10, 12};
    for (int i = 0; i < 6; ++i) {
        for (int j = 0; j < 6; ++j) {
            if (xs[i] * ys[j] == K) {
                cnt += 1;
            }
        }
    }

    

    cout << fixed << setprecision(12) << (double) cnt / (double) 36 << endl;

    return 0;
}