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


public class Main_yukicoder525 {

	private static Scanner sc;
	private static Printer pr;

	private static void solve() {
		String[] hm = sc.next().split(":");

		int hh = Integer.parseInt(hm[0]);
		int mm = Integer.parseInt(hm[1]);

		hh = (hh + (mm + 5) / 60) % 24;
		mm = (mm + 5) % 60;

		pr.printf("%02d:%02d\n", hh, mm);
	}

	// ---------------------------------------------------
	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);
		}
	}
}