CF 617A

#include<iostream>
#define lld long long
#define dbug(x) cout<<">"<<x<<endl

using namespace std;

int main()
{
 long long x;
 long long hp=5;
 
 while(cin>>x)
 {
  if(x%hp==0) cout<<x/hp<<endl;
  else cout<<(x/hp)+1<<endl;
  
   }
   
   return 0;
}