import java.io.*;
import java.text.*;
import java.util.*;
public class No525 {
	public static void main(String[] args) {
		try(BufferedReader input =new BufferedReader(new InputStreamReader(System.in))){
			String sTime[]=input.readLine().split(":");
			Calendar cTime = Calendar.getInstance();
			cTime.set(Calendar.HOUR_OF_DAY, Integer.parseInt(sTime[0]));
			cTime.set(Calendar.MINUTE, Integer.parseInt(sTime[1]));
			cTime.add(Calendar.MINUTE, 5);
			SimpleDateFormat sdf = new SimpleDateFormat("HH:mm");
			System.out.println(sdf.format(cTime.getTime()));
		}catch(Exception e){
			e.printStackTrace();
		}
	}
}