@b = sort {$a <=> $b} @b;
@a = sort {$a <=> $b} @a;
print "@b\n";

for (@a) {
  if (defined($b[$i])) {
    if (not $_ == $b[$i]) {
      push @c, $_
    } else {
      $i++
    }
  } else {
    push @c, @a[($j..$#a)];
    last;
  }
  $j++;
}

##</code><code>##

@c = grep { 
  defined($b[0]) and !($b[0] eq $_) or !shift @b
} sort {$a <=> $b} @a;