#include "bits/stdc++.h"
using namespace std;

int main(){
    int a[] = {8,12,16,18,20,24,12,18,24,27,30,36,20,30,40,45,50,60,28,42,56,63,70,84,44,66,88,99,110,132,52,78,104,117,130,156};
    int in, cnt=0;
    cin >> in;
    for(int i=0; i<36; i++){
        if(a[i]==in) cnt++;
    }
    printf("%.12lf\n", (double)cnt/36);
}