($b & $m[$p]) ne $a?return:substr($b, $p, 1) = "1";
    $d == 8?$s .= "$b|" if $s !~ /$b/:&z($_, $d+1) for 0..63;

##</code><code>##

    if (($b & $m[$p]) ne $a) { return; } 
    else { substr($b, $p, 1) = "1"; }    

    if ($d == 8) { $s .= "$b|" if $s !~ /$b/; }
    else { &z($_, $d+1) for 0..63; }