#include <map>
#include <set>
#include <list>
#include <cmath>
#include <queue>
#include <stack>
#include <cstdio>
#include <string>
#include <vector>
#include <complex>
#include <cstdlib>
#include <cstring>
#include <numeric>
#include <sstream>
#include <iostream>
#include <algorithm>
#include <functional>
  
#define mp       make_pair
#define pb       push_back
#define all(x)   (x).begin(),(x).end()
#define rep(i,n) for(int i=0;i<(n);i++)
  
using namespace std;
  
typedef    long long          ll;
typedef    unsigned long long ull;
typedef    vector<bool>       vb;
typedef    vector<int>        vi;
typedef    vector<vb>         vvb;
typedef    vector<vi>         vvi;
typedef    pair<int,int>      pii;
  
const int INF=1<<29;
const double EPS=1e-9;
  
const int dx[]={1,0,-1,0,1,1,-1,-1},dy[]={0,-1,0,1,1,-1,-1,1};


int main() {
    double ans = 0.0;
    int saikoro1[] = {2,3,5,7,11,13};
    int saikoro2[] = {4,6,8,9,10,12};

    int K;
    cin >> K;
    for (int i = 0; i < 6; i++) {
        for (int j = 0; j < 6; j++) {
            if (saikoro1[i] * saikoro2[j] == K) {
                ans += 1 / 36.0;
            }
        }
    }
    printf("%20.19f\n", ans);
    
    return 0;
}