/*************************************************************************
 *      This is a stack implementation that extends the LinkedList class
 *
 *************************************************************************/

import java.util.*;

public class StackByInheritance<T> extends LinkedList<T>
{
   public StackByInheritance()
   {
      super();
   }

 /**
   * Inserts an item onto the top of the stack.
   */
   public void push(T x)
   {
      addFirst(x);
   }

 /**
   *  Removes and returns the item at the top of this stack.
   */
   public T pop( ) throws StackException
   {
      if(isEmpty())
         throw new StackException("Stack is empty");
      else
         return remove();
   }

 /**
   *  Returns the top item without its removal
   */
   public T peek() throws StackException
   {
      return get(0);
   }



   public static void main(String[] args)
   {
      StackByInheritance<Integer> stk = new StackByInheritance<Integer>();
      stk.push(1);
      stk.push(5);
      stk.push(10);
      System.out.println(stk);
      System.out.println( stk.peek() );
      stk.pop();
      System.out.println( stk.peek() );
	}

}


	/**              StackException           **/


class StackException extends RuntimeException
{
   public StackException(String name)
   {
      super(name);
   }

   public StackException()
   {
      super();
   }
}