Chall mas rey

<?php
echo "Start : ";
$start = str_replace("\n","",fgets(STDIN));
echo "Rows : ";
$rows = str_replace("\n","",fgets(STDIN));
echo "Cols : ";
$cols = str_replace("\n","",fgets(STDIN));
for($a = 0;$a <= $rows;$a++){
    for($b = $start;$b < ($start+$cols);$b++){
        $arr[] = $a+$b;
        $str = implode(" ",$arr);
        $cs = chunk_split($str, $cols*2)."\n";
    }
    $ex = explode("\n",$cs);
    $row = $a+1;
    echo "Row ".$row." => ".$ex[$a]."\n";
}