MentorGroup

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

namespace _24_08_MentorGroup
{
    class MentorGroup
    {
        static void Main(string[] args)
        {
            var input = Console.ReadLine();

            var result = new Dictionary<string, Student>();

            while (input != "end of dates")
            {
                var inputNameDates = input.Split(new[] { ' ', ',' }, StringSplitOptions.RemoveEmptyEntries).Select(x => x.Trim()).ToArray();
                string name = inputNameDates[0];

                List<DateTime> datesToAdd = new List<DateTime>();

                if (inputNameDates.Length > 1)
                {
                    for (int i = 1; i < inputNameDates.Length; i++)
                    {
                        DateTime date = DateTime.ParseExact(inputNameDates[i], "dd/MM/yyyy", CultureInfo.InvariantCulture);
                        datesToAdd.Add(date);
                    }
                }
                Student studentToAdd = new Student();
                studentToAdd.Dates = new List<DateTime>();
                studentToAdd.Comments = new List<string>();
                studentToAdd.Dates.AddRange(datesToAdd);

                if (!result.ContainsKey(name))
                {
                    result.Add(name, new Student());
                    result[name] = studentToAdd;
                }
                else if (result.ContainsKey(name))
                {
                    result[name].Dates.AddRange(datesToAdd);
                }

                input = Console.ReadLine();
            }
            input = Console.ReadLine();

            while (input != "end of comments")
            {
                var inputNameComments = input.Split(new[] { '-' }, StringSplitOptions.RemoveEmptyEntries).Select(x => x.Trim()).ToArray();
                string name = inputNameComments[0];

                List<string> commentsToAdd = new List<string>();

                if (inputNameComments.Length > 1)
                {
                    for (int i = 1; i < inputNameComments.Length; i++)
                    {
                        commentsToAdd.Add(inputNameComments[i]);
                    }
                }
                if (result.ContainsKey(name))
                {
                    result[name].Comments.AddRange(commentsToAdd);
                }

                input = Console.ReadLine();
            }
            foreach (var student in result.OrderBy(x => x.Key))
            {
                Console.WriteLine($"{student.Key}");

                Console.WriteLine($"Comments:");

                foreach (var comment in student.Value.Comments)
                {
                    Console.WriteLine($"- {comment}");
                }

                Console.WriteLine("Dates attended:");
                foreach (var date in student.Value.Dates.OrderBy(x => x))
                {
                    Console.WriteLine($"-- {date:dd/MM/yyyy}");
                }

            }

        }
    }
    class Student
    {
        public List<string> Comments { get; set; }
        public List<DateTime> Dates { get; set; }
    }
}