NSDictionary 中的嵌套级别

问：

我从网络获取数据，然后创建 NSDictionary。这是我的 NSDictionary 的一部分：

 Car =             (
                                {
                    Number = 10;
                    Places =                     {
                        text = "001,003,004,022,023,024,026,027,029,030,031,033,035,036,038,040,042,043,044,047,048,049,050,051,052";
                    };
                    Seats =                     {
                        SeatsDn = 8;
                        SeatsLateralDn = 4;
                        SeatsLateralUp = 7;
                        SeatsUp = 6;
                    };
                },
                                {
                    Number = 11;
                    Places =                     {
                        text = "006,008,014,016,018,020,022,026,028,033,034,035,036,038,040,042,043,044,045,046,049,050,052";
                    };
                    Seats =                     {
                        SeatsDn = 2;
                        SeatsLateralDn = 3;
                        SeatsLateralUp = 7;
                        SeatsUp = 11;
                    };
                }
            );
            ClassService =             {
                Type = "1_type";
                text = "First type descr";
            };
            Owner =             {
                Country =                 {
                    Code = 27;
                    Name = "Country name";
                };
                Type = "\U041a\U0417\U0425/\U041a\U0417\U0425";
            };
            Tariff =             {
                text = 1122;
            };
            TariffService =             {
                text = 250;
            };
            TrainLetter = "\U0425";
            Type = "\U041f\U043b\U0430\U0446\U043a\U0430\U0440\U0442\U043d\U044b\U0439";
        }
    );

问题是有 2 个对象，它们有自己的 Number、Places、Seats，但在 ClassService 下，它们都有一对二。我怎么知道数字为 10 的对象有

ClassService = 
                    Type = "1_type";
                    text = "First type descr"

和

Tariff =             {
                    text = 1122;

数字为 11 的对象有

ClassService = 
                    Type = "1_type";
                    text = "First type descr"

和

Tariff =             {
                    text = 1122;

现在我正在使用这个：

NSarray *CarsNumbers = [[myDict valueForKey: @"Car"] valueForKey: @"Number"];`
NSarray *CarsTariffs = [[[myDict valueForKey: @"Car"] valueForKey: @"Tariff"] valueForKey: @"text"];
This way I see that `CarsNumbers.count = 2, `CarsTariffs.count = 1`

.我怎样才能做对？