import java.util.Iterator;
import java.util.SortedSet;
import java.util.TreeSet;
public class Main {
public static void main(String[] argv) throws Exception {
SortedSet set = new TreeSet();
set.add("b");
set.add("c");
set.add("a");
Iterator it = set.iterator();
while (it.hasNext()) {
Object element = it.next();
}
String[] array = (String[]) set.toArray(new String[set.size()]);
}
}