/* package whatever; // don't place package name! */

import java.util.*;
import java.lang.*;
import java.io.*;

/* Name of the class has to be "Main" only if the class is public. */
class Ideone
{
	public static void main (String[] args) throws java.lang.Exception
	{
		LinkedList <Integer> list = new LinkedList<Integer>() ;
        list.add(2); 
        list.add(3); 
        list.add(4); 
        list.add(1); 
        list.add(0); 
        list.addAll(list);
        System.out.println(list);
	}
}