Navreme Za Izpit

import java.util.Scanner;

public class NavremeZaIzpit {

    public static void main(String[] args) {
        Scanner scanner = new Scanner(System.in);
        String ivalidTime = "Invalid time";

        System.out.print("Exam Hours: ");
        int examHours = Integer.parseInt(scanner.nextLine());
        if (!(examHours >= 0 && examHours < 24)) {
            System.out.println();
            System.out.print(ivalidTime);
            return;
        }

        System.out.print("Exam Minutes: ");
        int examMinutes = Integer.parseInt(scanner.nextLine());
        if (!(examMinutes >= 0 && examMinutes < 60)) {
            System.out.println();
            System.out.print(ivalidTime);
            return;
        }

        System.out.print("Arrival Hours: ");
        int arrivalHours = Integer.parseInt(scanner.nextLine());
        if (!(arrivalHours >= 0 && arrivalHours < 24)) {
            System.out.println();
            System.out.print(ivalidTime);
            return;
        }

        System.out.print("Arrival Minutes: ");
        int arrivalMinutes = Integer.parseInt(scanner.nextLine());
        if (!(arrivalMinutes >= 0 && arrivalMinutes < 60)) {
            System.out.println();
            System.out.print(ivalidTime);
            return;
        }
        System.out.println();

        int examTime = (examHours * 60) + examMinutes;
        int arrivalTime = (arrivalHours * 60) + arrivalMinutes;
        int totalMinutesDiff = arrivalTime - examTime;
        int hoursDiff = Math.abs(totalMinutesDiff / 60);
        int minutesDiff = Math.abs(totalMinutesDiff % 60);

        if (totalMinutesDiff < -30) {
            System.out.println("Early ");
            if (hoursDiff == 1 && minutesDiff == 0) {
                System.out.printf("%d:%02d hour before the start", hoursDiff, minutesDiff);
            } else {
                System.out.printf("%d:%02d hours before the start", hoursDiff, minutesDiff);
            }
        }
        else if(totalMinutesDiff <= 0) {
            System.out.print("On time");
        }
        else {
            System.out.println("Late ");
            if (hoursDiff == 1 && minutesDiff == 0) {
                System.out.printf("%d:%02d hour after the start", hoursDiff, minutesDiff);
            } else {
                System.out.printf("%d:%02d hours after the start", hoursDiff, minutesDiff);
            }
        }

    }
}