Array
(
    [1] => Array
        (
            [0] => 11
            [1] => 12
            [2] => 13
            [3] => 
        )

    [2] => Array
        (
            [0] => 21
            [1] => 22
            [2] => 23
            [3] => 
        )

    [3] => Array
        (
            [0] => 31
            [1] => 
            [2] => 
            [3] => 
        )

)