Welcome to the forum, NA84! :D
I don't know how many forum members will have the time to devote to studying your assignment - just going through the funky functions like "printchau" is enough to make us reach for the Pepto. :p
Nevertheless, what are you stuck on? Did you get that box's alternate their first line char, and that modulo number mod 2==0 can be used to figure that out easily?
The more specific you can be, the better your help can be. Saying "I don't get it", is just saying the obvious, since you're here asking for help.
Take an example of input - how would you solve this input, in plain English. No code Just step by step, write it out, one statement per line. You'll build your program from this "skeleton" of an algorithm.
If you don't understand how to solve it like this, then you can't program the computer to do it, and you don't understand the problem yet, quite well enough.
Note, but put off the details for now, and focus on the things the pdf shows. Be sure you understand the BROAD hints the teacher is giving you, in that pdf, to solve this.
Drawing out one or two of these by hand, is a good way to see the patterns, and how they can be used in solving the problem.