import java.util.Scanner;

public class Main {
	public static void main(String[] args) {
		Scanner sc = new Scanner(System.in);
		int a = sc.nextInt();
		int b = sc.nextInt();
		String s = sc.next().substring(3);
		double zisa;
		int allMinute;
		if(s.charAt(0) == '+') {
			zisa = Double.valueOf(s.substring(1)) - 9.0;
			allMinute = (int)(24 * 60 * 60.0 + zisa * 60.0 + a * 60.0 + b * 1.0) % (24 * 60 * 60);
		} else {
			zisa = Double.valueOf(s.substring(1)) + 9.0;
			allMinute = (int)(24 * 60 * 60.0 - zisa * 60.0 + a * 60.0 + b * 1.0) % (24 * 60 * 60);
		}
		System.out.printf("%02d:%02d", allMinute / 60 % 24, allMinute % 60);

	}

}