import java.util.*;

class DataStructure implements Enumeration {

    String[] stuff = {"Alice", "Bob", "Carol", "Dave", "Ella", };
    
    
    int index = 0;

    public boolean hasMoreElements ()
    {
        if (index < stuff.length) {
            return true;
        }
        else {
            return false;
        }
    }
    

    public Object nextElement ()
    {
        String s = stuff[index];
        index ++;
        return s;
    }
    
    
    public Enumeration getEnumeration ()
    {
        index = 0;
        return this;
    }

}


public class DataStructureWithEnumeration {

    public static void main (String[] argv)
    {
        DataStructure ds = new DataStructure();
        Enumeration e = ds.getEnumeration();
        while (e.hasMoreElements()) {
            String s = (String) e.nextElement();
            System.out.println (s);
        }
    }

}