1. init an array to hold html tags (@html)
2. read $in (the htmlized text char by char)
3. $n++ for every non-html char (that is, !~ <.*> or <\/.*>
4. add the char (html or otherwise) to $out
5. push each html open tag (<.*>) in @html
6. on encountering a close tag (<\/.*>, 
   6.1. search @html for its corresponding open tag
   6.2. and delete it from the array
7. stop when $n reaches the limit
8. add closing tags for all remaining open tags in @html 
   in reverse order to the end of $out
9. spit $out