static void Main(string[] args)
        {
            StockData stocks = new StockData();

            stocks.InsertUpdateStocks("9:30:45:989 AM", "140");
            stocks.InsertUpdateStocks("9:40:00:000 AM", "100");
            stocks.InsertUpdateStocks("9:40:10:100 AM", "101");
            stocks.InsertUpdateStocks("9:40:10:200 AM", "109");
            stocks.InsertUpdateStocks("9:40:10:300 AM", "102");
            stocks.InsertUpdateStocks("9:40:10:400 AM", "103");
            stocks.InsertUpdateStocks("9:40:10:500 AM", "104");
            stocks.InsertUpdateStocks("9:40:10:600 AM", "105");
            stocks.InsertUpdateStocks("9:40:10:700 AM", "106");
            stocks.InsertUpdateStocks("9:40:10:800 AM", "107");
            stocks.InsertUpdateStocks("9:40:10:900 AM", "108");

            string output = stocks.GetStockPrices("9:40:00:000 AM");

            stocks.InsertUpdateStocks("9:50:00:000 AM", "130");
            stocks.InsertUpdateStocks("10:00:00:000 AM", "1070");
            stocks.InsertUpdateStocks("10:15:00:000 AM", "110");
            stocks.InsertUpdateStocks("10:20:45:589 AM", "160");
            stocks.InsertUpdateStocks("10:30:00:000 AM", "150");

            output = stocks.GetStockPrices("10:15:00:000 AM");

            stocks.InsertUpdateStocks("10:40:00:000 AM", "120");
            stocks.InsertUpdateStocks("12:40:00:000 PM", "1020");

            stocks.InsertUpdateStocks("9:40:00:000 AM", null);

            output = stocks.GetStockPrices("9:51:00:000 AM");
            stocks.InsertUpdateStocks("1:40:00:000 PM", "1420");
            stocks.InsertUpdateStocks("2:40:00:000 PM", "1920");
            stocks.InsertUpdateStocks("02:41:00:000 PM", "1980");
            output = stocks.GetStockPrices("02:41:00:000 PM");



            Console.ReadLine();
        }