import java.sql.Date;

public class RunWeek5 {
    public static void main(String[] args) {

        Student s1 = new Student("Shamil", "Arslanov", Date.valueOf("2000-02-17"));
        Student s2 = new Student("Marya", "Sayanova", Date.valueOf("2001-07-01"));
        Student_Girl g1 = new Student_Girl("Masha", "Xyz", Date.valueOf("1999-06-06"), true, true);

        Group data = new Group();
        data.addStudent(s2);
        data.addStudent(s1);
        data.addStudent(g1);
    }

}

public class Person {

    protected String firstName;
    protected String lastName;
    private static int ID = 1;
    protected int personId;

    public Person(String firstName, String lastName) {
        this.firstName = firstName;
        this.lastName = lastName;
        ++ID;
        this.personId = ID;
    }

    public Person() {
        this.firstName = "Null";
        this.lastName = "Null";
        this.personId = ++ID;
    }

    public String getFullName() {
        return firstName + " " + lastName;
    }
    public String getFullName(boolean reverse) {
        if (reverse) return lastName + " " + firstName;
        else return getFullName();
    }

    @Override
    public String toString() {
        return "Person{" +
                "firstName='" + firstName + '\'' +
                ", lastName='" + lastName + '\'' +
                ", personId=" + personId +
                '}';
    }
}

import java.sql.Date;


public class Student extends Person {
    private Date dateOfBirth;


    public Student(String firstName, String lastName, Date dateOfBirth) {
        super(firstName, lastName);
        this.dateOfBirth = dateOfBirth;
    }

    @Override
    public String toString() {
        return "Student{" +
                "dateOfBirth=" + dateOfBirth +
                ", firstName='" + firstName + '\'' +
                ", lastName='" + lastName + '\'' +
                ", personId=" + personId +
                '}';
    }
}