public class Person{

  private string name;
  private Date dateOfBirth, dateOfDeath;

  public Person (string name, Date dateOfBirth){
    this.name = name;
    this.dateOfBirth = dateOfBirth;
    this.dateOfDeath = null;
  }

  public string Name{
    get {return name;}
    set {name = value;}
  }

  public Date DateOfBirth{
    get {return dateOfBirth;}
  }

  public ushort AgeAsOf(Date d){
    return (ushort)(d.Year - dateOfBirth.Year);
  }

  public bool Alive(){
    return dateOfDeath == null;
  }

  public override string ToString(){
    return "Person: " + name + " " + dateOfBirth;
  }

}