import java.util.Scanner;

public class Main {

	public static void main(String[] args) {
		Scanner sc = new Scanner(System.in);
		String t = sc.next();
		int m = Integer.valueOf(t.substring(0, 2)) * 60 + Integer.valueOf(t.substring(3, 5));
		m = (m + 5) % (24 * 60);
		System.out.printf("%02d:%02d\n", m / 60, m % 60);
	}
}