import java.util.Map;
import java.util.HashMap;

public class Addressbook2 {
	private Map addresses = new HashMap();

	/* pre: address and p are not null
	 * post: address of person has been registered in
	 * address book
	 */
	public void note(Person p, String address){
		addresses.put(p, address);
	}

	/* pre: p is not null
	 * post: return is the address of p, or null
	 * 	if p is not in the address book
	 */
	public String lookup(Person p){
		return (String)addresses.get(p);
	}
}