import java.util.TreeSet;
import java.util.Iterator;

public class TestTreeSet{
    public static void main(String[] args) {
        TreeSet ts = new TreeSet();
        ts.add("orange");
        ts.add("banana");
        ts.add("apple");
        ts.add("grape");

        Iterator it = ts.iterator();
        while(it.hasNext()){
            String fruit = (String)it.next();
            System.out.println(fruit);    
        }
    }
}