import java.util.*; 
public class LinkedListDemo 
{ 
public static void main(String[] args) 
{ 
LinkedList<String> ll = new LinkedList<>(); 
ll.add("first"); ll.add("second"); ll.add("fourth"); 
System.out.println("Contents: " + ll); 
System.out.println(); 
ll.add(2, "third"); ll.addFirst("zero"); 
System.out.println("Contents: " + ll); 
System.out.println(); 

} 
}