import java.io.*;
import java.util.*;


public class Main_yukicoder652 {

	private static Scanner sc;
	private static Printer pr;

	private static void solve() {
		int a = sc.nextInt();
		int b = sc.nextInt();
		String s = sc.next();

		int sign = s.charAt(3) == '+' ? 1 : -1;
		int c = s.indexOf('.');
		if (c == -1) {
			c = s.length();
		}
		int tz = Integer.parseInt(s.substring(4, c)) * 10;
		if (c < s.length()) {
			tz += Integer.parseInt(s.substring(c + 1, s.length()));
		}
		tz *= sign;

		a = (a - 9 + 24) % 24;

		int jp = a * 60 + b;
		jp *= 10;

		int sq = (jp + tz * 60 + 60 * 24 * 10) % (60 * 24 * 10);
		sq /= 10;

		pr.printf("%02d:%02d\n", sq / 60, sq % 60);
	}

	// ---------------------------------------------------
	public static void main(String[] args) {
		sc = new Scanner(System.in);
		pr = new Printer(System.out);

		solve();

		pr.close();
		sc.close();
	}

	private static class Printer extends PrintWriter {
		Printer(PrintStream out) {
			super(out);
		}
	}
}