Condense Array to Number

<?php
$array = explode(' ', readline());
$condensed = $array;
while (count($array) > 1) {
    $condensed = [];
    for ($i = 0; $i < count($array) - 1; $i++) {
        $condensed[] = intval($array[$i]) + intval($array[$i + 1]);
    }
    $array = $condensed;
}
echo $condensed[0];