i was solving maths section from CSES, because I wanna work on my weak part first. But I got stuck in the starting problem of CSES problem set. The problem link is: https://www.cses.fi/problemset/task/2164. I was thinking for it for 2 days, but not even a bug hit my head, then I looked the tutorial and realised the problem was not that difficult actually.

It's not like im weak in maths or whatsoever, But i didn't even implement what i write on the sheet for the problem? Also Internet is full with resources that I know, and many of it are usless for me. So i need some precise docs/yt_links that I can follow along to get better in maths_part in 1-2 months of training.