Hello, Codeforces!

We are excited to invite you to DeepInfra Round 1 (Codeforces Round 1126, Div. 1 + Div. 2), which will take place on Oct/10/2026 18:05 (Moscow time)! Note the unusual start time of the round.

You will have 3 hours to solve 8 problems, one of which is divided into subtasks.

The problems were prepared by employed and reviewed carefully by nifeshe. We have put a lot of care into creating and testing this problemset, and we hope you will enjoy solving the problems as much as we enjoyed preparing them!

A huge thank you to everyone who helped bring this round to life:

• nifeshe for coordinating the round and being funny, cool, and smart!
• Dominater069 for the early review of the problems.
• EvenImage, AksLolCoding, ApraCadabra, Euclid73, linearspace, Mohammad_Hacker, naneosmic, nik_exists, omsincoconut, Pie_TealCompressorDragon, Rising-coder, Rvess, Sana, zyadhany, _______________________, FetFot, A_G, flammifer, and catgirl for testing the round and helping us improve the problemset.
• nifeshe for translating the statements into Russian.
• MikeMirzayanov and KAN for the Codeforces and Polygon platforms.

Honorable Mentions

A special thanks to our most disciplined testers, who joined the testing phase and successfully resisted the temptation to open a single problem:

cadmiumky, Um_nik, _istil, Intellegent, cgmoreda, sammyuri, Error_Yuan, cry, SpyrosAliv, and Arpa.

Thank you for your statistical contribution to the testing group's headcount.

Score distribution will be announced later.

And now, a few words from today's sponsor!

Hello Codeforces!

We’re excited to welcome you to DeepInfra Round 1

At DeepInfra, we build high-performance AI infrastructure that makes running the world’s best AI models fast, reliable, and accessible. We work across the entire inference stack—from GPUs to APIs—solving challenging engineering problems with a strong focus on performance and efficiency.

Our team has deep roots in Codeforces and competitive programming. One of us even competed in Codeforces Beta Round 50, so we’ve been around since the early days!

We prepared great prizes for the winners:

• Top 3: 1000 USDT + merch
• 4-6: 250 USDT + merch
• 7-10: 150 USDT + merch
• Random 10 from the top 100 (rank 11-100): merch

We’re growing! If you enjoy problem solving and want to work on challenging systems at the intersection of AI and infrastructure, we’d love to hear from you.

To apply for Software Engineering interns and full-time positions, fill in the application form and we will be in touch.

Good luck to everyone competing — have fun, and we’ll see you on the leaderboard!

— The DeepInfra Team

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

Please note that prize delivery to certain countries, states, provinces, or territories may be subject to applicable sanctions, trade restrictions, or other legal requirements. We will make every reasonable effort to deliver prizes to all eligible winners, subject to any restrictions that may apply.

See you on the leaderboard. Good luck, have fun, and may your submissions turn green!