04. Back In 30 Minutes

import java.util.Scanner;

public class P04BackIn30Minutes {
    public static void main(String[] args) {
        Scanner scanner = new Scanner(System.in);

        int initHours = Integer.parseInt(scanner.nextLine());
        int initMinutes = Integer.parseInt(scanner.nextLine());

        //1:46 + 30 -> 1*60 = 60 + 46 + 30 = 136 -> 2:16
        int allMinutes = (initHours * 60) + initMinutes + 30;

        int hours = allMinutes / 60;
        int minutes = allMinutes % 60;

        if (hours > 23) {
            hours = 0;
        }

        System.out.printf("%d:%02d", hours, minutes);
    }
}