gistfile1.txt

function plural($num, $single, $plural, $plural4) {
    $num_mod_10 = $num % 10;
    $num_mod_100 = $num % 100;
    return $num === 1 || $num_mod_100 > 20 && $num_mod_10 === 1 ?
            $single :
            (($num_mod_100 < 10 || $num_mod_100 > 20) && $num_mod_10 <= 4 ?
                    $plural4 : $plural);
}