import java.util.Comparator;

class PersonComparator implements Comparator<Person> {
  public int compare(Person p1, Person p2) {
    if (p1.lastName.compareTo(p2.lastName) < 0) {
      return -1;
    } else if (p1.lastName.compareTo(p2.lastName) > 0) {
      return 1;
    } else if (p1.firstName.compareTo(p1.firstName) < 0) {
      return -1;
    } else if (p1.firstName.compareTo(p1.firstName) > 1) {
      return 1;
    } else {
      return 0;
    }
  }
}