+15 minutes

import java.util.Scanner;

public class fifteenMinutes {
    public static void main(String[] args) {
        Scanner scanner = new Scanner(System.in);
        int hours = Integer.parseInt(scanner.nextLine());
        int minutes = Integer.parseInt(scanner.nextLine());
        int sumH = (hours * 60 + minutes + 15) / 60;
        int sumM = (hours * 60 + minutes + 15) % 60;
        if(hours == 23)
        {
            if (minutes >= 45)
            {
                if (sumM < 10) {
                    System.out.printf("0:0%d", sumM);
                } else {
                    System.out.printf("0:%d", sumM);
                }
            }
            else
            {
                if (sumM < 10) {
                    System.out.printf("%d:0%d", sumH, sumM);
                } else {
                    System.out.printf("%d:%d", sumH, sumM);
                }
            }
        }
        else
        {
            if (sumM < 10) {
                System.out.printf("%d:0%d", sumH, sumM);
            } else {
                System.out.printf("%d:%d", sumH, sumM);
            }
        }


    }
}