// Student.java

public class Student {
    private String firstName;
    private String lastName;
    private int id;
    private double gpa;
    private int credits;
    private static int nextId = 1000;

    public Student() {
        firstName = "";
        lastName = "";
        id = nextId;
        nextId++;
        gpa = 0.0;
        credits = 0;
    }

    public Student(String fname, String lname) {
        firstName = fname;
        lastName = lname;
        id = getNextId();
        gpa = 0.0;
        credits = 0;
    }

    private static int getNextId() {
        return nextId++;
    }

    public void addCourse(int creds, String grade) throws IllegalArgumentException {
        double gradeGPA;
        if (grade.equals("A")) gradeGPA = 4.0;
        else if (grade.equals("A-")) gradeGPA = 3.7;
        else if (grade.equals("B+")) gradeGPA = 3.3;
        else if (grade.equals("B")) gradeGPA = 3.0;
        else if (grade.equals("B-")) gradeGPA = 2.7;
        else if (grade.equals("C+")) gradeGPA = 2.3;
        else if (grade.equals("C")) gradeGPA = 2.0;
        else if (grade.equals("C-")) gradeGPA = 1.7;
        else if (grade.equals("D+")) gradeGPA = 1.3;
        else if (grade.equals("D")) gradeGPA = 1.0;
        else if (grade.equals("F")) gradeGPA = 0.0;
        else throw new IllegalArgumentException();

        gpa = ((gpa * credits) + (gradeGPA * creds)) / (credits + creds);
        
        if (gradeGPA > 0) {
            credits += creds;
        }
    }

    public void report() {
        System.out.println(firstName + ", " + lastName + "\t" + id + "\t"
                + String.format("%.2f", gpa) + "\t" + credits);
    }

    public boolean canGraduate() {
        return (credits >= 120) && (gpa >= 2.0);
    }

    public String getYear() {
        if (credits < 30) return "First year";
        else if (credits < 60) return "Sophomore";
        else if (credits < 90) return "Junior";
        else return "Senior";
    }
}