// Jim Herrero - CH20TEST
import java.util.*;
public class test20
{
  public int countZeroes(ListNode head)
  {
    int count = 0;
    for(ListNode node = head; node != null; node = node.getNext())
      if(node.getValue() == 0)
        count++;
  }
  public void remove(Object obj)
  {
    if(head.getValue().equals(obj))
    {
      head = head.getNext();
      return;
    }
    for(ListNode node = head; node != null; node = node.getNext())
      if(node.getNext().getValue().equals(obj))
      {
        node.setNext(node.getNext().getNext());
        return;
      }
  }
  //23 - no clue
  public Object removeFirst()
  {
    Object temp = head.getValue();
    head = head.getNext();
    tail.setNext(head);
    head.setPrevious(tail);
    return temp;
  }
  private void fixBackLinks()
  {
    //25 - no clue
  }
}