import java.util.*;

class Personne {
  String nom;
  int age;
  public Personne(String nom, int age) {
    this.nom = nom; this.age = age;
  }
  public String toString() { return "Nom: "+nom+", age: "+age; }
}

class HashSetTest {
  public static void main(String[] args) {
    Set s = new HashSet();
    s.add(new Personne("Pierre", 23));
    s.add(new Personne("Anne", 20));
    s.add("Université");
    s.add("Marne-la-Vallée");
    System.out.println(s);
    Set t = (Set) ((HashSet) s).clone();
    System.out.println(s.size());
    Iterator i = t.iterator();
    while(i.hasNext())
      if (i.next() instanceof Personne) 
	i.remove();
    System.out.println(t);
  }
}