import java.util.Collection;
import java.util.LinkedList;

public class Pila<E> extends LinkedList<E> {


    //copia los elmentos de otra coleccion
    public Pila(Collection< ? extends E> c){
        for(E e : c)
            empujar(e);
    }

    public Pila(){ super();}

    public void empujar(E e ){
        super.addFirst(e);
    }

    public E remover(){
        return super.removeFirst();
    }

    public boolean estaVacia(){
        return super.size() == 0;
    }

    public String toString(){
        return super.toString();
    }
}

import java.util.*;

public class DemoDePila {
    public static void main(String[]args) {
        Pila<Integer> p = new Pila<>(Arrays.asList(1, 2, 3));
        System.out.println(p);
    }
}