## before

Array
(
    [0] => Array
        (
            [0] => 400
            [1] => 484
            [2] => 576
        )

    [1] => Array
        (
            [0] => 196
            [1] => 256
            [2] => 324
        )

    [2] => Array
        (
            [0] => 64
            [1] => 100
            [2] => 144
        )

    [3] => Array
        (
            [0] => 4
            [1] => 16
            [2] => 36
        )
)

## after
Array
(
            [0] => 400
            [1] => 484
            [2] => 576
            [3] => 196
            [4] => 256
            [5] => 324
            [6] => 64
            [7] => 100
            [8] => 144
            [9] => 4
            [10] => 16
            [11] => 36
)