Как конвертировать JSON в многомерный массив?

string[,] cities = new string[,] { };
            for (int i = 0; i < cities.Length; i++)
            {
                Querys.AddCity(cities[i]);//так не делается походу
            }

public static void AddCity(string cityName, string countryName)
        {
            using (SqlConnection connection = new SqlConnection(ConnectionString))
            {
                string sql = "[dbo].[AddCity]";

                using (SqlCommand command = new SqlCommand(sql, connection))
                {
                    DataTable dataTable = new DataTable();

                    command.CommandType = CommandType.StoredProcedure;

                    command.Parameters.Add("@param", SqlDbType.NVarChar, 30);
                    command.Parameters["@param"].Value = cityName;
                    command.Parameters.Add("@param2", SqlDbType.NVarChar, 30);
                    command.Parameters["@param2"].Value = countryName;

                    connection.Open();
                    command.ExecuteNonQuery();
                    connection.Close();

                }
            }
        }

CREATE PROCEDURE [dbo].[AddCity]
	@param nvarchar (MAX),
	@param2 nvarchar (MAX)
AS
BEGIN
DECLARE @CountryID NVARCHAR(MAX)
SET @CountryID = (SELECT Countrys.Id from dbo.Countrys where Countrys.Name = @param2)
	INSERT INTO [dbo].[Cities]
           ([Name],[CountryID])
     VALUES
           (@param, @CountryID)

		 
END

{ { "Турция", "Город в турции" }, { "Турция", "Город в турции2" }, { "Греция", "Город в Греции" } };

public class CityInfo
{
    public string CountryName { get; set; }
    public string CityName { get; set; }
}

public class RootObject
{
    public List<CityInfo> cities { get; set; }
}