02-returned spaces
02-add function is better now
03-Improved repeat and first_word functions
04-Removed unnecessary
03,04-used join instead strip
05-raverser function in one line
07-greeting function in one line
Order of functions changed
09-Improved
10-Improved
10-Improved
11-Improved
12-rpn_calculator
11-reduced
11-reduced
13-xml_document