<?php

$passwords = explode("\n", file_get_contents('input.txt'));

$number_of_good_passwords = 0;

foreach ($passwords as $password) {
    $parts = explode(' ', $password);
    if (count($parts) === 3) {
        [$min, $max] = explode('-', $parts[0]);
        $letter = $parts[1][0];
        $word = $parts[2];
        $chars = count_chars($word, 1);
        if ($min <= $chars[ord($letter)] && $max >= $chars[ord($letter)]) {
            $number_of_good_passwords++;
        }
    }
}

echo $number_of_good_passwords;
exit(0);