import java.util.Scanner;

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

        int hours = Integer.parseInt(scanner.nextLine());
        int minutes = Integer.parseInt(scanner.nextLine());

        minutes = minutes + 15;

        if (minutes > 59) {
            minutes = minutes - 60;
            hours = hours + 1;
            }

        else if (hours >= 24)
            hours = hours - 24;

        if (minutes < 10)
            System.out.println(hours + ":0" + minutes);

         else
            System.out.println(hours + ":" + minutes);
    }
}