import java.util.NoSuchElementException;

$/**$

A linked list is a sequence of nodes with efficient

element insertion and removal. This class

contains a subset of the methods of the standard

java.util.LinkedList class.

$*/$

public class LinkedList

$\{$

private Node first;

$/**$

Constructs an empty linked list.

$*/$

public LinkedList$()$

$\{$

first $=$ null;

$\}$

public Object removeLast$()$

$\{$

if $($first $==$ null$)$ return