Hello, Codeforces!

We're excited to invite you to TLX Regular Open Contest #42!

Key details:

• Contest links: TLX

• Time: 13th October 2025, 13:05 UTC

• Writer: Pyqe

• Duration: 2 hours 30 minutes

• Problems: 7

• Scoring distribution: 100 — 200 — 300 — 350 — 500 — 700 — 800

I would like to thank:

• tzaph_ for the coordination.
• rama_pang, user202729, and Kinon for their help in testing the problems and giving feedback.
• fushar for the TLX platform.

Please register for the contest and I encourage you to read all problems!

UPD: Added scoring ditribution!

UPD2: The contest is over!

You can upsolve the problems here. Editorials are available in the upsolve link!

Thank you for participating and making Kantipa happy! I hope you all enjoyed my MS Paint drawings! See you on the next contest!

UPD3: Mistake in problem E, contest unrated

After the contest, it has been discovered that the solution codes for problem E by the writer and testers have the same mistake, which makes the tests for problem E invalid. Since this clearly causes unfairness in the contest, the contest has to unfortunately be unrated. We deeply apologize for the inconvenience.

We are now working on fixing problem E after the contest for upsolving.

UPD4: Rejudge for problem E

Since the contest is already unrated, all submissions for problem E during the contest have been rejudged using the corrected jury solution so that the scoreboard more closely reflects the true results (though still not perfect). We apologize once again for the inconvenience.