Hello, Codeforces! I'm pleased to announce the 5th stage of the 2nd Universal Cup. It will be held from October 14th to October 15th.

The contest was prepared for you by the SPbSU LOUD Enough team (tranquility, nikgaevoy and Kaban-5), a bronze medalist of ICPC World Finals in Dhaka. We (the authors) would also like to thank Gassa, snarknews and SoshkinRoman for some useful feedback and technical assistance. And, of course, we would like to thank the organizers of Universal Cup for letting us hold our contest as a stage of Universal Cup and share it with a wider audience.

This contest was first used in the Petrozavodsk Programming Camp Winter 2023, and also appeared in the 2023 ICPC Training Camp powered by Huawei and the Hello Muscat 2023 Bootcamp. If you participated in any of those, please refrain from participating in this stage of the Universal Cup.

It is important to note that this stage is much more difficult than an average ICPC regional. Solving even a couple of problems is already an achievement.

We think that all problems contain interesting ideas in them and we are delighted to share them with the community. In particular, we think that teams preparing for ICPC World Finals have a lot to learn from our contest. Good luck and have fun!

Let's meet in the comments to discuss the problems after the last time window for the contest finishes! We will update the post with a link to the editorial shortly after that. You are encouraged to share different approaches and talk about the problemset in general.

Update. As promised, you can find the editorial here: https://acm.math.spbu.ru/trains/231014_northern/
It is a bit sketchy, so feel free to ask additional questions about the problems and their solutions.

You can participate in the contest in the following time windows:

• 02:00 (UTC) on Saturday ~ 07:00 (UTC) on Saturday
• 05:00 (UTC) on Saturday ~ 10:00 (UTC) on Saturday
• 08:00 (UTC) on Saturday ~ 13:00 (UTC) on Saturday
• 11:00 (UTC) on Saturday ~ 16:00 (UTC) on Saturday
• 13:00 (UTC) on Saturday ~ 18:00 (UTC) on Saturday
• 15:00 (UTC) on Saturday ~ 20:00 (UTC) on Saturday
• 18:00 (UTC) on Saturday ~ 23:00 (UTC) on Saturday

Please refer to https://ucup.ac/rules?season=2 if in doubt.

Contest link: https://contest.ucup.ac

Universal Cup Scoreboard: https://qoj.ac/ucup/scoreboard