#include <bits/stdc++.h>
int n, d, f;
int main() {
  scanf("%d", &n);
  if (n > 5) {
    d = n / 5;
    f = n % 5;
    if (f > 0)
      f = d + 1;
    else
      f = d;
    printf("%d", f);
  } else
    printf("1");
  return 0;
}
