#include<bits/stdc++.h>
using namespace std;
#define rep(i,n) for(ll i=0;i<n;i++)
#define repl(i,l,r) for(ll i=(l);i<(r);i++)
#define per(i,n) for(ll i=(n)-1;i>=0;i--)
#define perl(i,r,l) for(ll i=r-1;i>=l;i--)
#define fi first
#define se second
#define pb push_back
#define ins insert
#define pqueue(x) priority_queue<x,vector<x>,greater<x>>
#define all(x) (x).begin(),(x).end()
#define CST(x) cout<<fixed<<setprecision(x)
#define rev(x) reverse(x);
using ll=long long;
using vl=vector<ll>;
using vvl=vector<vector<ll>>;
using pl=pair<ll,ll>;
using vpl=vector<pl>;
using vvpl=vector<vpl>;
 ll MOD=1000000007;
 ll MOD9=998244353;
 int inf=1e9+10;
 ll INF=1e18;
 ll dy[8]={1,0,-1,0,1,1,-1,-1};
 ll dx[8]={0,1,0,-1,1,-1,1,-1};
template <typename T> inline bool chmax(T &a, T b) {
  return ((a < b) ? (a = b, true) : (false));
}
template <typename T> inline bool chmin(T &a, T b) {
  return ((a > b) ? (a = b, true) : (false));
}

int main(){
  vl v1={2,3,5,7,11,13},v2={4,6,8,9,10,12};
  ll k;cin >> k;
  long double ans=0;
  rep(i,6){
    rep(j,6){
      if(k==v1[i]*v2[j])ans++;
    }
  }
  CST(20);
  cout << ans/36 <<endl;
}