Петр

function sliceText(str, maxlength) {
  return (str.length > maxlength) ?
    str.slice(0, maxlength - 3) + '...' : str;
}

public class UserModel
    {
        public string FirstName { get; set; }
        public string LastName { get; set; }

        public List<AccountModel> Accounts { get; set; } = new List<AccountModel>();

    }

public class AccountModel
    {
        public string AccountType { get; set; }
        public string Email { get; set; }
        public string Password { get; set; }

        public AccountModel(string account_type, string email, string password)
        {
            this.AccountType = account_type;
            this.Email = email;
            this.Password = password;
        }
    }

_userList.Add(new UserModel() {

                FirstName = "Jack",
                LastName = "The Sparrow",
                Accounts = new List<AccountModel>()
                {
                    new AccountModel("Yandex","rambler@mail.ru","321312"),
                    new AccountModel("Yandex","rambler@mail.ru","321312"),
                }
            });

class Program
    {
        static void Main(string[] args)
        {
            Console.WriteLine("Enter your name: ");
            string name = Console.ReadLine();
            char[] charArr = name.ToCharArray();

            Array.Reverse(charArr);
            string reName = string.Join("",charArr);
            Console.WriteLine(reName);
            Console.ReadKey();
        }
    }