Thanks for the wonderful feedback, makes me happy :) I'd prefer to help readers with hints rather than making solutions public. Give it your best shot and if y

Thanks for the wonderful feedback, makes me happy :) I'd prefer to help readers with hints rather than making solutions public. Give it your best shot and if you are stuck with no where to go, you can contact me via email/twitter mentioned in Preface chapter. Hint for this question: there are multiple possible solutions. I used -P option for its skipping feature (see 'Perl Compatible Regular Expressions' chapter) to avoid the code blocks.