A linked list has four nodes containing the values 10, 20, 30, and 40 (in that order) and is defined by a reference to its first node, head. The method doTheTrick below returns a reference to the head of the changed list. How many nodes will the changed list have and what values will be stored in them?

public ListNode doTheTrick(ListNode head)

{

if (head == null || head.getNext() == null)

return head;

ListNode newHead = head.getNext();

newHead = doTheTrick(newHead);

head.setNext(newHead.getNext());

newHead.setNext(head);

return newHead;

}