import java.util.*;

class Samp09 {
	public static void main(String[] args){
		Comparator<String> cs = Collections.reverseOrder();
		System.out.println(cs.getClass().getName());
		TreeSet<String> tss = new TreeSet<String>(cs);
		tss.add("abc");
		tss.add("def");
		tss.add("ghi");
		for(String s: tss){
			System.out.println(s);
		}
	}
}