public class useDEList{
   public static void main(String[] args){
      DoubleEndedListInterface list = new DEList();

      list.addLast("1");
      list.addFirst("a");
      list.addFirst("b");
      list.addLast("2");
      list.addLast("3");
      list.addFirst("c");
      list.addLast("4");

      System.out.println("first = " + list.getFirst());
      System.out.println("last = " + list.getLast());
      list.display();

      list.removeLast();
      list.removeFirst();
      list.display();

      while(!list.isEmpty()){
		  list.removeLast();
	  }

	  list.addFirst("d");
	  list.display();
   }
}