import java.util.Scanner;

public class Main {
    public static void main(String[] args) {
        Scanner console = new Scanner(System.in);
        int first = Integer.parseInt(console.nextLine());
        int second = Integer.parseInt(console.nextLine());
        int third = Integer.parseInt(console.nextLine());
        // за секунди ,съм дал рандом числа
        int total = first + second + third;
        int mins = 0;
         if(total > 59 && total <= 119) {
         mins++;
         total -= 60;
         } else if (total > 120) {
         mins += 2;
         total -= 120;
         }
         System.out.printf("%d:%02d", mins, total);

    }
}