OAC -02/1

$file = file_get_contents('input1.txt');

$lines = explode("\n", $file);
$i = 0;

foreach ($lines as $line) {
    $expl = explode(':', $line);

    $characters = trim($expl[1]);

    $numbers_character = explode('-', $expl[0]);
    $max_character = explode(' ', $numbers_character[1]);

    $min = (int) $numbers_character[0];
    $max = (int) $max_character[0];
    $character = trim($max_character[1]);

    $count_match = substr_count($characters, $character);

    if (($count_match >= $min) && ($count_match <= $max)) {
        $i++;
    }
}

var_dump($i);