import java.util.*;

public class Main {
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        char[] arr = sc.next().toCharArray();
        int hour = (arr[0] - '0') * 10 + arr[1] - '0';
        int minute = (arr[3] - '0') * 10 + arr[4] - '0';
        minute += 5;
        hour += minute / 60;
        hour %= 24;
        minute %= 60;
        System.out.printf("%02d:%02d", hour, minute);
    }
}