public int deleteAllNodesWithEvenValues()
    {
        // Delete all the nodes in the list containing even values, returning how many were deleted.
		ListNode current = head;
		int counter = 0;
		current = current.next;

		while(current.next != head){
			if(current.data % 2 == 0){
				ListNode temp = current.next;
				current.next = temp.next;
				counter++;
			}else{
				current = current.next;

			}
		}


        return counter-1;
    }