function stoneBlocks(array $h): int
{
    $height = [];
    $index  = $blocks = 0;

    foreach ($h as $i) {
        while ($index > 0 && $height[$index - 1] > $i) {
            $index--;
        }
        if ($index > 0 && $height[$index - 1] === $i) {
            continue;
        }

        $height[$index] = $i;
        $blocks++;
        $index++;
    }

    return $blocks;
}