import java.util.Iterator;

class Stabel<T> implements Iterable<T> {

  private Node forste = null;

  private class Node {
    Node neste = null;
    T verdi;

    Node(T t) {
      verdi = t;
    }
  }

  public void leggPaa(T t) {
    Node nyNode = new Node(t);
    nyNode.neste = forste;
    forste = nyNode;
  }

  public void print() {
    for (T t : this) {
      System.out.println(t);
    }
  }


  public T taAv() {
    if (forste == null) {
      return null;
    }
    T retVerdi = forste.verdi;
    forste = forste.neste;
    return retVerdi;
  }

  @Override
  public Iterator<T> iterator() {
    return new StabelIterator();
  }

  private class StabelIterator implements Iterator<T> {
    Node itter = null;

    public T next() {
      if (itter == null) {
        itter = forste;
        return itter.verdi;
      }
      itter = itter.neste;
      return itter.verdi;
    }

    public boolean hasNext() {
      if (itter == null) {
        return forste != null;
      }
      return itter.neste != null;
    }
  }
}