import java.text.SimpleDateFormat;
import java.util.*;

class Main {
	static Scanner sc = new Scanner(System.in);
	public static void main(String[] args) {
		
		Calendar cl = Calendar.getInstance();
		String s = sc.next();
		int h = Integer.parseInt(s.charAt(0)==0?s.substring(1,2):s.substring(0,2));
		int m = Integer.parseInt(s.charAt(3)==0?s.substring(4,5):s.substring(3,5));
		cl.set(Calendar.HOUR_OF_DAY, h);
		cl.set(Calendar.MINUTE, m);
		cl.add(Calendar.MINUTE, 5);
		SimpleDateFormat sdf = new SimpleDateFormat("HH:mm");
		System.out.println(sdf.format(cl.getTime()));
		
		
	}
}