can someone tell me how this code work?

Question

https://code.sololearn.com/cQQpNp4ntXw6/?ref=app

Answer 1

still couldn't understand what I get
https://code.sololearn.com/cr6X5Pq4O8Zw/?ref=app

Answer 2

I tried this too ..

Answer 3

Ahh got it! thank you a lot;)