import java.util.Scanner;

public class TimePlus15Minutes {
    public static void main(String[] args) {
        Scanner scan = new Scanner(System.in);

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

        if(minutes >= 45){
            minutes += 15 - 60;

            if (hours == 23){
                hours = 0;
            }
            else{
                hours++;
            }
        }
        else{
            minutes += 15;
        }

        System.out.printf("%-15d:%15d", hours, minutes);
    }
}