/* package whatever; // don't place package name! */

import java.util.*;
import java.lang.*;
import java.io.*;

/* Name of the class has to be "Main" only if the class is public. */
class Ideone
{
    private static int[] SOSUU = new int[]{2,3,5,7,11,13};
    private static int[] GOSEI = new int[]{4,6,8,9,10,12};
    public static void main (String[] args) throws java.lang.Exception
    {
        // your code goes here
        BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
        int n = Integer.parseInt(br.readLine());
        int cnt = 0;
        for(int s:SOSUU)
        for(int g:GOSEI){
            if(s*g==n){
                cnt++;
            }
        }
        System.out.println(cnt/36.0);
    }

}