import java.util.*;

class Index extends TreeMap {
  public void put(int page, String mot) {
    Set numeros = (Set) get(mot);
    if (numeros == null) {
      numeros = new TreeSet();
      put(mot, numeros); // la ``vraie'' méthode put
    }
    numeros.add(new Integer(page));    
  }
  public void print() {
    Set clés = keySet();
    for (Iterator i = clés.iterator(); i.hasNext(); ) {
      String c = (String) i.next();
      System.out.println(c + " " + get(c));
    }
  }
}

class IndexTest {
  public static void main(String[] args) {
    Index index = new Index();
    index.put(22,"Java");
    index.put(23,"Itérateur");
    index.put(25,"Java");
    index.put(25,"Map");
    index.put(25,"Java");
    index.put(29,"Java");
    index.print();
  }
}