to clarify, I assume you're using a multi-dimensional array, where each element contains another two-element array?

$array[0] = [1,12];
$array[1] = [1,13];
$array[2] = [2,14];
#etc...
[download]

or are these literal strings?

$array[0] = "(1,12)";
$array[0] = "(1,13)";
$array[0] = "(2,14)";
#etc...
[download]