$arr1[0] [0] = 00
$arr1[0] [1] = 01
$arr1[1] [0] = 10
$arr1[1] [1] = 11

$arr2[0] [0] = 00
$arr2[0] [1] = 01
$arr2[1] [0] = 10
$arr2[1] [1] = 11