Hi all, I found questions for the Russian, South Korean, and Polish olympiads here:

https://www.acmicpc.net/category/500

https://www.acmicpc.net/category/55

https://szkopul.edu.pl/p/default/problemset_eng/oi

For Russia, what's the precise difference between ROI, the Russia High School Programming Contest, the Russia Team High School Programming Contest, the Russian Olympiad for Schoolchildren in Informatics, and the Russian Olympiad in Informatics Regional?

For South Korea, what's the precise difference between the KOI 1st competition, 2nd competition, and city/province finals?

For Poland, what's the precise difference between the 1st, 2nd, and 3rd rounds?

Thanks!