Hello Codeforces!

The series of Educational Rounds continues thanks to the support of the Computer Science and Artificial Intelligence (CSAI) program at Neapolis University Pafos, with scholarships provided by JetBrains.

Educational Codeforces Round 187 (Rated for Div. 2) will start on Feb/25/2026 17:35 (Moscow time).

This round will be rated for the participants with rating lower than 2100. It will be held on extended ICPC rules. The penalty for each incorrect submission until the submission with a full solution is 10 minutes. After the end of the contest, you will have 12 hours to hack any solution you want. You will have access to copy any solution and test it locally.

You will be given 6-7 problems and 2 hours to solve them.

The problems were invented and prepared by Adilbek adedalic Dalabaev, Ivan BledDest Androsov, Maksim Neon Mescheryakov, Roman Roms Glazov, Maks FelixArg Novotochinov and me. Also, huge thanks to Mike MikeMirzayanov Mirzayanov for great systems Polygon and Codeforces.

Good luck to all the participants!

Our friends at Neapolis University Pafos also have a message for you:

Admission is now open for the BSc in Computer Science & Artificial Intelligence. Up to 40 full scholarships from the JetBrains Foundation will be awarded this year, covering tuition, accommodation, insurance, visa fees, and a €300 monthly stipend.

JetBrains Blackbox Cup 2026 Join our new unique coding competition, happening on March 15, 2026.

• Imagine joining a project with no documentation and no backlog. Your mission: explore the system, uncover hidden logic, and start solving tasks — step by step, through experimentation and smart guesses.
• AI tools are welcome! AI assistants and modern developer tools are fully allowed — resourcefulness is part of the challenge.
• Two leagues: Junior — high school students & Senior — university students, graduates, and professionals.

Registration closes on March 13.

Winning the Blackbox Cup can also boost the chances of getting a fully-funded JetBrains Foundation scholarship for BSc CSAI at Neapolis University Pafos(extra points on the entrance test).

See you!

UPD: Editorial is out

Hello again! After merely eight days (personal record!) from my last contest, I gladly invite you to Codeforces Round 1082 (Div. 1, Div. 2) — which will be held on Feb/23/2026 17:35 (Moscow time)! For both divisions, you will be given $$$\mathbf{2.5}$$$ hours to solve $$$\mathbf{7}$$$ problems, where some problems may be divided into subtasks.

All problems of the contest are invented and prepared by myself.

I would like to thank:

• Sugar_fan for his excellent coordination.
• Alexdat2000 for Russian translations.
• Um_nik for pre-reviewing problems.
• sammyuri for MVP testing (crazy, outstanding amount of contribution to the round!).
• Proof_by_QED, satyam343, reirugan for VIP testing (big contribution to the round!).
• EvenImage, StarSilk for red-black testing.
• cadmiumky, __baozii__, prabowo, Intellegent, A_G, nifeshe for red testing.
• weirdflexbutok, misteg168 for yellow testing.
• fisher199, shcal, Vikas_soni, madlogic, Hori, wakanda-forever for purple testing.
• Argentum47, vodacbaoan, simplelife for blue testing.
• MikeMirzayanov and KAN for great platforms Codeforces and Polygon.
• You for participating!

The score distribution is as follows:

• Div. 1: $$$(750+500) - 1250 - 1750 - 2250 - 3000 - (2750+1500) - 5000$$$
• Div. 2: $$$750 - 1250 - (1000+750) - 1750 - 2500 - 3000 - (2750+2500)$$$

I wish you a thrilling experience in the round. Good luck and have fun!

UPD1: Added score distribution.

UPD2: Editorial (now complete!)

Also, congratulations to the winners!

• Div. 1:

1. tourist
2. ecnerwala
3. ksun48
4. jiangly
5. potato167

• Div. 2 (Maybe subject to change when cheaters are found):

1. JuanSign
2. Joskmo
3. rns_pis2
4. Miaoborui
5. foolnotfooling

Hello Codeforces !!!

I am very excited to invite you to participate in Codeforces Round 1081, which will be held on Feb/21/2026 17:35 (Moscow time)! You will be given $$$\mathbf{2}$$$ hours to solve $$$\mathbf{6}$$$ problems. This round will be rated for all participants with rating below 2100.

This is my first time hosting an official Codeforces round, and all the problems are authored by me. I hope you will enjoy the round.

This round would not be possible without the help of the following people:

• Proof_by_QED for excellent coordination and improving the problems.
• flamestorm and ScarletS for initial coordination of the round.
• Alexdat2000 for russian statement translation.
• All the testers for testing and sharing valuable feedback: __baozii__, YuukiS, N_z__, sammyuri, Ari, Error_Yuan, maomao90, _istil, Markadiusz, nifeshe, prvocislo, cry, temporary1, mwen, ItsNotMeItsYou, Friedrich, fishy15, ApraCadabra, amsraman, AlperenT, efishel, wakanda-forever, chromate00, nyaruhodo, Prashant_10434.
• MikeMirzayanov and KAN for the great Codeforces and Polygon platforms.
• You for participating in this round.

Score distribution: $$$500−1000−1250−1750−2250−3000$$$.

Good Luck & Have Fun !

UPD 1: Editorial

UPD 2: Congratulations to the winners:

Div 1:

1. maspy
2. peti1234
3. StarSilk
4. Rubikun
5. potato167

Div 2:

1. XtremeXSPC
2. WithYoshino
3. Dom_inic
4. koukirocks_so_cute
5. aaa_Pigeon2

Oh hello there. I, chromate00, am back! Oh no, I hope you are not misunderstanding me, I'm not pulling a joke on the announcement this time. I'm too busy for that right now. So here's the (mostly copy-pasted) announcement of Codeforces Round 1080 (Div. 3).

Anyways. Starting from Feb/15/2026 17:45 (Moscow time), you will be given $$$\mathbf{7}$$$ or $$$\mathbf{8}$$$ problems to be solved in $$$\mathbf{2.5}$$$ hours.

The round will be hosted by rules of educational rounds (extended ICPC). Thus, all solutions will be judged on preliminary tests during the round, and after the round, there will be a 12-hour phase of open hacks. After the open hack phase, all accepted solutions will be rejudged on successful hacks. Also, note that there is no score distribution but the usual penalty of 10 minutes for each wrong submission, following the rules of educational rounds.

Remind yourself that only the trusted participants of the third division will be included in the official standings table. As it is written by link, this is a compulsory measure for combating unsporting behavior. To qualify as a trusted participant of the third division, you must:

• take part in at least five rated rounds (and solve at least one problem in each of them)
• not have a rating of 1900 or higher at any moment in time.

Regardless of whether you are a trusted participant of the third division or not, if your rating is less than 1600, then the round will be rated for you (unless you register unrated).

Also, note the rule restricting the use of AI. If you are caught while breaking this rule, you will be sent to cry's new basement on Mars without oxygen.

This round is made possible by the help of the following people:

• Vladosiya for coordinating the round (and translating the statements);
• Proof_by_QED for his continued support;
• Dominater069 for red-black testing;
• awoo, __baozii__, catgirl, ttamx, sammyuri, Intellegent for red testing;
• Arpa, omsincoconut, spike1236, beaaaan, -firefly-, temporary1, turska, Friedrich for yellow testing,
• SpyrosAliv, reirugan, tin.le2, yse; YamOCHca, conjectureguy, Edeeva for purple testing;
• ananthak, Ermiooo159, my_bloody_valentine, ai4youej, itz_pabloo, bestial-42-centroids for blue testing;
• ALnQ417, ne_justlm for cyan testing;
• MikeMirzayanov and KAN for great platforms Codeforces and Polygon.

I hope that you will enjoy the contest. Good luck and have fun!

UPD1: Editorial has been posted

Greetings Codeforces community!

We are excited to announce the Constructor Open Cup 2026, our annual online programming competition organized by Constructor University and JetBrains Foundation.

What is the Constructor Open Cup?

Constructor Open Cup is an online contest organized by Constructor University and JetBrains Foundation to promote interest in computer science, data science, software development, and software engineering.

Put your knowledge and skills to the test in this 4-hour competition and stand a chance to walk away with a scholarship for a bachelor's degree in Software, Data and Technology (BSc SDT) at Constructor University, Germany’s #1 private university*!

Constructor Open Cup timetable

February 2 — February 12, 2026 | Practice Round

Get familiar with the testing environment during this practice round.

February 12, 2026 at 2 PM (UTC) | Main Round

You will have 4 hours to complete a series of algorithmic programming tasks. Registration closes 1 hour before the start of the contest.

Hello, Codeforces!

sevlll777 and I are glad to invite you to participate in Codeforces Round 1079 (Div. 1) and Codeforces Round 1079 (Div. 2). Both rounds will take place at Feb/11/2026 17:35 (Moscow time). There will be 6 problems in each round, some of them can be divided into several subtasks. You will have 3 hours to solve all the problems. The round will be held according to the Codeforces rules and will be rated for both divisions.

At least one problem will be interactive, so we highly recommend to read guide for interactive problems before the contest.

We would like to thank:

• Um_nik for pre-reviewing the round.
• FairyWinx for coordination and helping with problem ideas/preparation.
• MikeMirzayanov and KAN for the best platform.
• SomethingNew, A_G for VIP testing.
• SomethingNew, antontrygubO_o, Um_nik, BurnedChicken for nutella testing.
• PvPro, zeemanz, A_G, k1r1t0, BledDest, triple__a, awoo for red testing.
• Noobish_Monk, Kolychestiy, antonis.white for orange testing.
• madlogic, robotolev for purple testing.
• Matrosk1n, egor4444ik, slash0t, deni1000, dan00ile, Mox_Taest3r, dariasaligina for blue testing.
• IceHydra, bessarab for cyan testing.
• Uznik_Postmoderna for green testing.
• Pimerroc, Dima-prog-coder, Manatth for gray testing.

UPD 1: The score distribution is as follows:

• Div. 1: $$$500 - 750 - (750 + 750) - 2250 - (2000 + 1000) - 3500$$$
• Div. 2: $$$500 - 1000 - 1250 - 1500 - (1500 + 1500) - 4000$$$

UPD 2: Editorial

Wishing everyone good luck and high ratings!

Hello, Codeforces!

This Sunday there will be a Moscow Olympiad for Young Students. This contest is prepared by Moscow Olympiad Scientific Committee that you may know by Moscow Open Olympiad, Moscow Team Olympiad, Metropolises Olympiad and All-Russian olympiad in the name of Keldysh.

We are glad to invite you to Codeforces Round 1078 (Div. 2) based on the problems of this olympiad, which will take place on Feb/08/2026 12:05 (Moscow time). Note the unusual time of the round. The round will be held according to the Codeforces rules and will be rated for all participants with rating below 2100.

Problems of this competition were prepared by silvvasil, Semen07, allvik66, dope, teraqqq guided by TheEvilBird, grphil and Helen Andreeva.

Thanks to FairyWinx for the round coordination, and also thanks for MikeMirzayanov и KAN for Codeforces and Polygon platforms, which was used to prepare problems of this olympiad.

We also thank:

• t.ravnushkin, KiKoS, didedoshka, feblokas, makrav, blook, zhiganov_v, lewc, gmusya for testing the main Olympiad problems;

• __baozii__, _istil, ArSarapkin, fishy15, PvPro, madlogic, -firefly-, FelixArg for testing the round;

• RP-1, stepanov.aa for the preparing Olympiad problems that were not included in the round.

The scoring will be available later.

UPD: Scoring distribution: 500 — 1000 — 1750 — 2000 — 2500 — (1750 + 1750)

UPD: Since the round is based on an onsite olympiad, viewing other participants' submissions and upsolving will be available starting from 12:00 UTC

UPD: Until 13:00 UTC due technical reason

UPD: Editorial

Hello, Codeforces!

After years of hard work, we are euphoric to invite you to participate in Codeforces Round 1077 (Div. 1) and Codeforces Round 1077 (Div. 2), which will be held at Jan/29/2026 17:35 (Moscow time). For both divisions, you will be given $$$7$$$ problems and $$$3$$$ hours to solve them. For at least one of the divisions, one of the problems will be divided into two subtasks.

The problems are invented and prepared by Bronya_H, Error_Yuan, StarSilk, Tobo, __baozii__ and me.

We would like to thank:

• SSerxhs for his Superb, Stellar, Extraordinary, Reliable, Xcellent, Helpful and Supportive coordination.
• Alexdat2000 for Russian translations.
• zeemanz and bookcat for providing some ideas that were not ultimately used.
• cry for inventing a basement of infinite capacity to imprison cheaters.
• errorgorn, tiger2005, EnofTaiPeople, and dXqwq for black opal testing.
• geospiza, Aging1986, Sugar_fan, Duck_sajin, qkm66666, AYTDD, Fantasy_Blue, Intellegent, SATSKY_2025target_LGM, _istil, wangmarui, rucaco, fallleaves01, permutation, nifeshe, and A_G for ruby testing.
• Proof_by_QED, sh1ziku, 0x3F, K_tian, aori., sszcdjr, hxu10, CirnoNine, and chennie for topaz testing.
• fatalerror, Fusu, -WIDA-, shendeliliang, and Liang_SYEA for amethyst testing.
• Kato_Shoko, TEYL, clearlove13, Non-origination, chromate00, fr200110217102, and XiaoXia for sapphire testing.
• imhighshou and Clclclcl for aquamarine testing.
• MikeMirzayanov for his obsidian Codeforces and Polygon platform.

The score distribution is below.

Div. 1: $$$750 - 1250 - 1750 - 2000 - 2250 - (2000 + 3500) - 3000$$$.

Div. 2: $$$500 - 1000 - 1500 - 2000 - 2500 - 2750 - 3000$$$.

We sincerely hope you can enjoy the problems. Good luck and see you on the field !

UPD1: The hacks are disabled for problems A-D in Div 2, and for problems A-B in Div 1. We have final tests consisting of pretests and hacks for all problems.

UPD2: Editorial