import java.util.*;
import java.io.*;

class PhoneBook implements Serializable
{
  public void addEntry(BookEntry entry)
  {
    phonebook.put(entry.getPerson(), entry);
  }

  public BookEntry getEntry(Person key)
  {
    return (BookEntry)phonebook.get(key);
  }

  public PhoneNumber getNumber(Person key)
  {
    return getEntry(key).getNumber();
  }

  private HashMap phonebook = new HashMap();
}