获取数组中的数组键值

Question

是否有可能将33值分开？下面，我添加我的结果，我只想获得33值（第一个数组键值）。

Array
(
    [33] => Array
        (
        [StudentClass] => Array
            (
                [18884] => Array
                    (
                        [count_total] => 5
                    )

                [29754] => Array
                    (
                        [count_total] => 2
                    )

                [446] => Array
                    (
                        [count_total] => 1
                    )

                [600] => Array
                    (
                        [count_total] => 1
                    )

            )