There are a few problems here. As friedo (Update: and others too, apparently) already pointed out, you're using anonymous hashref constructors where you appear to want a simple list grouping construct. Also, you're attempting to assign entire arrays as the value for $b[0] and $b[1], but array values can only be scalars (not arrays, or hashes).

Put bluntly, it appears that you don't know a whole lot of Perl and are just trying things at random. Perhaps you should spend some more time learning the language, using a resource designed specifically for that? Maybe a stop over to http://learn.perl.org/ would do you well.