[hello][/hello]

gistfile1.php

<?php

function count_nested_shortcodes( $shortcode ) {
	// each shortcode uses the "[" chatacter twice. The first is of the opening tag, the last is for the closing tag. 
	// The main shortcode also has 2 occurances. Since we're looking for the nested shortcodes, we'll ignore the main one by subtracting 2 from the total outcome
	return (int) ( substr_count( $shortcode, '[' ) / 2 ) - 2;
}

Maor take a look let me know what did I do wrong :(

$max_depth) { $max_depth = $depth; } } } return $max_depth; } ``` ?>