class DLNode {
  private Object element;
  private DLNode next, prev;
  DLNode() { this(null, null, null); }
  DLNode(Object e, DLNode p, DLNode n) {
    element = e;
    next = n;
    prev = p;
  }
  void setElement(Object newElem) { element = newElem; }
  void setNext(DLNode newNext) { next = newNext; }
  void setPrev(DLNode newPrev) { prev = newPrev; }
  Object getElement() { return element; }
  DLNode getNext() { return next; }
  DLNode getPrev() { return prev; }
}