struct slistEl
{
  slistEl * next;
  char data;
};

class slist
{
  public:
    slistEl * head;

    slist();  // konstruktor
    ~slist(); // destruktor
    void pop_front();
    void push_front(int k);
};

void slist::push_front(int k)
{
  slistEl * p;

  p = new slistEl;
  p->next = head;
  p->data = k;
  head = p;
}

void slist::pop_front()
{
  slistEl * p = head;

  if(p)
  {
    head = p->next;
    delete p;
  }
}