#include <bits/stdc++.h>
using namespace std;
int main()
{
    vector<int> c{2,3,5,7,11,13};
    vector<int> p{4,6,8,9,10,12};
    int k,ans=0;
    cin>>k;
    for(int i=0;i<6;i++){
        if(k%c[i]==0){
            ans+=count(p.begin(),p.end(),k/c[i]);
        }
    }
    cout<<fixed<<setprecision(17)<<ans/36.0<<endl;
}