4. Autonomy

<?php
$widthFree = readline();
$lengthFree = readline();
$heigthFree = readline();
$commands = "";

        $volume = $widthFree * $lengthFree * $heigthFree;
        $sumVolume = 0;
        while ($sumVolume <= $volume) {
            $commands = readline();
            if($commands == "Done"){break;}
            else {
            $sumVolume += intval($commands);}
        }
        if ($sumVolume > $volume) {
            printf("No more free space! You need %d Cubic meters more.", $sumVolume - $volume);
        } else printf("%d Cubic meters left.", $volume - $sumVolume);