Hello Codeforces!

I am glad to invite you to participate in Spectral::Cup 2026 Round 3 (Codeforces Round 1110, Div. 1 + Div. 2), which will start on Jul/16/2026 17:45 (Moscow time). You will be given 2 hours and 30 minutes to solve 8 problems, where one problem will be split into subtasks. Also, there is at least one interactive problem, so you are recommended to read the guide to interactive problems if you have not encountered them before.

Note that hacks will be disabled for problems A to D.

All problems are authored and prepared by myself.

Note the rule restricting the use of AI. If you are caught breaking this rule, you will be thrown into SSerxhs's basement. For your own well-being, I suggest adhering to the rules.

I would like to thank the following people for helping make this round possible!

• SSerxhs for his/her satisfactory coordination.
• Alexdat2000 for translating the statements to Russian.
• nifeshe for "I will solve this problem today" — nifeshe.
• StarSilk, EvenImage, tiger2005 for nutella testing.
• zeemanz, 0.1w33hw3, nifeshe, _istil, SATSKY_2025target_LGM for red testing.
• Seele_H, Proof_by_QED, GUAIKATTO, CReatiQ for orange testing.
• -WIDA-, Liang_SYEA, Argentum47, wakanda-forever for purple testing.
• fr200110217102, simplelife, XiaoXia, acmtoohard, big-mktx for blue testing.
• yuki_Ishijo for cyan testing.
• Whalica for green testing.
• MikeMirzayanov and KAN for the incredible Codeforces and Polygon platforms.

Score distribution:

$$$500 - 1000 - 1250 - (1500 - 1000) - 2500 - 3000 - 3500 - 5000$$$

update:

Tutorial has been published: tutorial

Now a few words from our sponsor.

🏁The final round of Spectral::Cup 2026 is coming!

This round is special to us. Not only will it conclude our three-round Spectral::Cup tournament, but it will also take place during our company’s birthday month — Spectral::Technologies turned 7 this July 🎉

Round 3 is the final part of our birthday celebration. The rest is in this video 😄

We are already sending out the merch from the two previous rounds — here is a little preview of what is on its way. A personal approach is important to us, so every prize is made especially for its recipient.

Prizes for Spectral::Cup Round 3

Top 30 participants in Round 3 will receive personalized hoodies.

🏆Final Prizes for Spectral::Cup 2026

The final round is also your last chance to improve your position in the overall standings. Your final score is the sum of your two best results across all three rounds, calculated using the GP500 scoring system.

Among the participants who finish the Cup in the final Top 500, 30 randomly selected participants will receive a prize box.

Top 15 by final cup score will receive a Claude subscription.

Top 3 by final cup score will receive:

• 1st place — MacBook Pro

• 2nd place — iPad Pro

• 3rd place — WHOOP

Top 3 winners can choose to receive the equivalent value in USDT instead.

Last but not least, if you would like to join Spectral Team check out our Quant roles:

• Junior Quant – 150–180k USD + profit sharing
• Middle Quant – 240–320k USD + profit sharing
• Senior Quant – 360–500k USD + profit sharing

We’re also hiring for C++, ML, and DevOps roles. Complete the application form to explore career opportunities with us.

Apply

PS We reserve the right to apply strict compliance checks when finalizing the results in order to prevent unfair participation and rule violations.

Good luck!

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