package m.shin;
import java.util.Scanner;
public class Con525 {

	public static void main(String[] args) {
		Scanner s = new Scanner(System.in);
		String str = s.nextLine();
		s.close();
		int h = Integer.parseInt(str.substring(0,2));
		int m = Integer.parseInt(str.substring(3,5));

		if(m > 54){
			h = (h + 1) % 24;
		}
		m = (m + 5) % 60;

		if(h < 10){
			str = "0" + h + ":";
		}else{
			str = Integer.toString(h) + ":";
		}
		if(m < 10){
			str += "0" + m;
		}else{
			str += Integer.toString(m);
		}

		System.out.println(str);


	}

}