Hi Codeforces!
It's our pleasure to announce the 10th edition of Bubble Cup. Bubble Cup is a programing competition organized by Microsoft Development Center Serbia (MDCS), and will be held this weekend. Contest will take place on Saturday, 2nd of September at 09:30 UTC, in Belgrade, Serbia. Live results will be available on the official Bubble Cup website (results will be frozen during the last hour of the competition). Winners will be announced at the closing ceremony.
Just like the two previous editions, this final will be followed by an online mirror competition on Codeforces. Mirror will take place on Sunday, 3rd of September at 10:00 UTC. Contest will last for 5 hours and ACM ICPC rules will be applied. It will be a competition for teams of 1-3 members. There will be at least eight problems.
We kindly ask participants of the onsite final to hold off discussing problems publicly until the mirror is over.
Contest was mainly prepared by employees of MDCS. We give our thanks to Nikolay Kalinin (KAN) for the round coordination, Mike Mirzayanov (MikeMirzayanov) and the team behind Codeforces and Polygon platforms. Special thanks goes to knightL for helping out with problem testing.
The contest will be unrated. The reason for this is because rules of this contest are not common for Codeforces. Also, it is only a mirror of an onsite competition.
Editorial will be available in the booklets section on the Bubble Cup website a few hours after the online mirror ends.
EDIT:
Here you can find mirror contests from the previous two finals:
Bubble Cup 8 — Finals [Online Mirror]
Bubble Cup 9 — Finals [Online Mirror]
EDIT #2:
The contest has started. You can see the live results on the Bubble Cup website.
EDIT #3:
Here are the results of the onsite finals.
The top three winning teams of the online mirror contest:
1. tourist, VArtem
2. zigui, molamola., dotorya
3. Um_nik, Kronecker
Complete rankings are listed on this link.
Congrats to all winners!
You can find contest editorial here.
EDIT #4:
Thank you for your comments. While our official and ainta's solution matched on the test cases provided we found out from the comments here that there are some edge cases we didn't handle correctly and don't know how to handle properly given the constraints. Because of that we decided to remove the problem from the set and reset all penalties people received from the incorrect submissions. Sincere apologies to everyone affected by this.