public class Student extends Person {
    private String studentId;
    private double gpa;

    public Student(String name, int age, String studentId, double gpa) {
        super(name, age);
        this.studentId = studentId;
        this.gpa = gpa;
    }

    @Override
    public String getRole() { return "Student"; }

    @Override
    public String getExtraInfo() {
        return "ID: " + studentId + ", GPA: " + gpa;
    }
}