using System;
using System.IO;
using System.Linq;
using System.Collections.Generic;
using System.Text;

public class Program
{

    public void Proc()
    {
        string[] inpt = Reader.ReadLine().Split(' ');
        int localH = int.Parse(inpt[0]);
        int localM = int.Parse(inpt[1]);
        decimal jisa = decimal.Parse(inpt[2].Substring(3));
        jisa -= 9;

        localM += (int)(jisa * 10) % 10 * 6;
        while(localM>=60) {
            localM -= 60;
            localH++;
        }
        while(localM<0) {
            localM += 60;
            localH--;
        }
        localH += (int)jisa;
        while(localH<0) {
            localH += 24;
        }
        localH = localH % 24;
        string ans = localH.ToString("00") + ":" + localM.ToString("00");
        Console.WriteLine(ans);
    }

    public class Reader
    {
        private static StringReader sr;
        public static bool IsDebug = false;
        public static string ReadLine()
        {
            if (IsDebug)
            {
                if (sr == null)
                {
                    sr = new StringReader(InputText.Trim());
                }
                return sr.ReadLine();
            }
            else
            {
                return Console.ReadLine();
            }
        }
        private static string InputText = @"


00 05 UTC+8.5


";
    }

    public static void Main(string[] args)
    {
#if DEBUG
        Reader.IsDebug = true;
#endif
        Program prg = new Program();
        prg.Proc();
    }
}