#include <bits/stdc++.h>
using namespace std;
int main() {
  int x;
  cin >> x;
  if (x <= 5) {
    cout << 1;
  } else {
    int ct = 0;
    while (x > 0) {
      x = x - 5;
      ct++;
    }
    cout << ct;
  }
}
