import java.util.*;
import java.util.stream.Stream;
import java.time.*;
import java.time.format.*;

public class No525 {
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
		String[] t = sc.next().split(":");
		LocalDateTime tt = LocalDateTime.of(2016, 1, 1, Integer.parseInt(t[0]), Integer.parseInt(t[1]));
		// DateTimeFormatter dtf = DateTimeFormatter.ofPattern("yyyy/MM/dd HH:mm");
		tt = tt.plusMinutes(5);
		// dtf.format(tt);
		String h = String.valueOf(tt.getHour());
		String m = String.valueOf(tt.getMinute());
		System.out.println((h.length() == 1 ? "0" + h : h) + ":" + (m.length() == 1 ? "0" + m : m));
	}
}