import java.util.*;

public class Main
{
    public static void fill(Collection c) {
        for (int i = 1; i <= 3; i++) {
            c.add(i);
        }
    }
  
    public static void print(Collection c) {   
        Iterator i = c.iterator();
        while(i.hasNext()) {  
            System.out.println(i.next());
        }
    }
    
    public static void main(String[] args) {
        List list1 = new ArrayList();        
        fill(list1);
        print(list1);
        
        List list2 = new LinkedList();        
        fill(list2);
        print(list2);
    }
}