On Time for the Exam

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace On_Time_for_the_Exam
{
    class Program
    {
        static void Main(string[] args)
        {
            int correctHour = int.Parse(Console.ReadLine());
            int correctMinutes = int.Parse(Console.ReadLine());
            int arriveHour = int.Parse(Console.ReadLine());
            int arriveMinutes = int.Parse(Console.ReadLine());

            int correctTime = correctHour * 60 + correctMinutes;
            int arriveTime = arriveHour * 60 + arriveMinutes;
            int earlyMinutes = correctTime - 30;

            int diff = 0;

            if (arriveTime == correctTime)
            {
                Console.WriteLine("On time");
            }
            else if (arriveTime > correctTime)
            {
                Console.WriteLine("Late");

                diff = arriveTime - correctTime;
                int hours = diff / 60;
                int minutes = diff % 60;
                if (hours > 0)
                {
                    Console.WriteLine("{0}:{1:D2} hours after the start", hours, minutes);
                }
                else
                {
                    Console.WriteLine("{0} minutes after the start", minutes);
                }
            }
            else if (arriveTime >= earlyMinutes)
            {
                Console.WriteLine("On time");
                diff = correctTime - arriveTime;
                int hours = diff / 60;
                int minutes = diff % 60;
                if (hours > 0)
                {
                    Console.WriteLine("{0}:{1:D2} hours before the start", hours, minutes);
                }
                else
                {
                    Console.WriteLine("{0} minutes before the start", minutes);
                }

            }
            else
            {
                Console.WriteLine("Early");
                diff = correctTime - arriveTime;
                int hours = diff / 60;
                int minutes = diff % 60;
                if (hours > 0)
                {
                    Console.WriteLine("{0}:{1:D2} hours before the start", hours, minutes);
                }
                else
                {
                    Console.WriteLine("{0} minutes before the start", minutes);
                }
            }
        }
    }
}