Exam Schedule

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

namespace ExamSchedule
{
    class ExamSchedule
    {
        static void Main(string[] args)
        {
            string startHour = Console.ReadLine();
            string startMinute = Console.ReadLine();
            string partOfDay = Console.ReadLine();

            int examhours = int.Parse(Console.ReadLine());
            int examMinutes = int.Parse(Console.ReadLine());
            CultureInfo culture = CultureInfo.GetCultureInfo("en-US");
            string timeExamStart = startHour + ":" + startMinute + " " + partOfDay;
            DateTime startTime = Convert.ToDateTime(timeExamStart, culture);
            DateTime endHours = startTime.AddHours(examhours);
            DateTime endTime = endHours.AddMinutes(examMinutes);
            Console.WriteLine(endTime.ToString("hh:mm:tt", culture));
        }
    }
}