$re = '/^(?:[1-9]|[1-9][0-9]|[12][0-9]{2}|3[0-5][0-9]|36[0-6])$/m';
$str = 'Example Matches:
1
99
366
159
Example Match Failures:
01
001
099
367
999
0';
preg_match_all($re, $str, $matches, PREG_SET_ORDER, 0);
// Print the entire match result
var_dump($matches);
Please keep in mind that these code samples are automatically generated and are not guaranteed to work. If you find any syntax errors, feel free to submit a bug report. For a full regex reference for PHP, please visit: http://php.net/manual/en/ref.pcre.php