interface Ordered {
  public boolean less(Ordered x);
}

class OrderedString implements Ordered {
  String s;

  OrderedString(String s) 
  { this.s = s; }

  public boolean less(Ordered t)
  { return s.compareTo(((OrderedString)t).s) < 0; }
}

class OrderedInt implements Ordered {
  int i;

  OrderedInt(int i) 
  { this.i = i; }

  public boolean less(Ordered h)
  { return i < ((OrderedInt)h).i; }
}

class Person {
  int date;
  String name;
}

abstract class OrderedPerson extends Person implements Ordered {
  abstract public boolean less(Ordered x);
}

class OrderedPerson1 extends OrderedPerson {

  public boolean less(Ordered f)
  { return date < ((OrderedPerson1)f).date; }
}

class OrderedPerson2 extends OrderedPerson {

  public boolean less(Ordered f)
  { return name.compareTo(((OrderedPerson2)f).name) < 0; }
}

// Use the class variable datesort to determine the sorting criterion

class OrderedPerson3 extends OrderedPerson {

  public static boolean datesort;

  public boolean less(Ordered f)
  { 
    if (datesort) 
      return date < ((OrderedPerson3)f).date; 
    else
      return name.compareTo(((OrderedPerson3)f).name) < 0; 
  }
}