Hello Codeforces!!!

I am more than happy to invite you to my first solo round Codeforces Round 1107 (Div. 3), which starts on Jun/30/2026 17:35 (Moscow time). You will be given $$$7$$$ problems and $$$2$$$ hours $$$15$$$ minutes to solve them.

All the problems were authored and prepared by me.

The round will be hosted by the 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 — rank will be determined by the number of problems solved, followed by penalty; wrong submissions will incur the usual penalty of 10 minutes, following the rules of educational rounds.

Remember that only the trusted participants of the third division will be included in the official standings table. As it is written in the 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)
• do not have a point of 1900 or higher in the rating.

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.

I would like to thank the following people for making this round possible:

• cry for his careful coordination.
• Vladosiya for providing Russian translations.
• _istil, Proof_by_QED, simplelife, kevinxiehk, temporary1, reirugan, Jrke, Forge, Intellegent, Argentum47, __baozii__, awesomeguy856, SpyrosAliv, omsincoconut, expertaq, skellyboi05, yse, M.Y., Edeeva, nik_exists, fishy15, madlogic, chromate00, singharpit2492, Arpa, DivinePunishment, Lilypad for testing the round and providing valuable feedback.
• MikeMirzayanov and KAN for the legendary platforms.

Additionally, if you are a tester of Codeforces Round 1095 (Div. 2) and you are rated for Division 3, I would request you not participate in the round, as it is possible you have seen some tasks before.

I would be looking forward to your participation, and I hope you love the problems.

GLHF.

Editorial

Hello, Codeforces!

We are glad to announce that Codeforces Round 1106 (Div. 2) will take place at Jun/28/2026 17:35 (Moscow time). The round will be rated for participants with rating below $$$2100$$$. You will be offered $$$6$$$ problems, with $$$2$$$ hours to solve them.

All problems were created and prepared by lewc, KotlechkovEgor and me.

We express our HUGE gratitude to the following people, without whom the round could not have taken place:

• 74TrAkToR for incredible coordination.
• Um_nik and 244mhq for preliminary review of the round.
• zhiganov_v, wxhtzdy, JYJin, abc864197532 and OG_Matveychick1 for red testing of the round.
• XaRDKoDblCH, pskobx, Mark_Pr and _LeMur_ for orange testing of the round.
• _liravel_, mirach0ck, MaksimXD, AmirGG, VitaliiV, KluydQ and EduardoBrito for purple testing of the round.
• Yassia, FLYDEB, semwin2008, itz_pabloo, YF_YUSUF and kinoud for blue testing of the round.
• BoberVitalya228, grigalex40, Redk1tli and AdunAdunov for cyan testing of the round.
• Ghuiko for green testing of the round.
• awrt_xz for gray testing of the round.
• MikeMirzayanov and KAN for the wonderful platforms Codeforces and Polygon.
• You for participating!

The scoring distribution is as follows:

UPD: Editorial has been posted

UPD2: Congratulations to the winners!

Official participants

• zddtuus

• IzhitskiyTimofey

• sahilsingh177

• modongtao

• nbufe2422510022

Unofficial participants

• Otomachi_Una

• Hamed_Ghaffari

• AksLolCoding

• paracompact

• Rubikun

你好，Codeforces!

We are delighted to invite you to participate in Codeforces Round 1105 (Div. 1) or Codeforces Round 1105 (Div. 2), both of which will be held on Jun/27/2026 17:35 (Moscow time).

For both division 1 and division 2, you will be given $$$2.5$$$ hours to solve $$$6$$$ problems in each division.

The problems were authored and prepared by Gold14526, Milkcat2009 and wangmarui.

We would really like to thank the following people for making this round possible:

• Um_nik for the preliminary review of the round
• cadmiumky for the great coordination.
• Alexdat2000 for providing Russian translations.
• hcywoi and Network_Error who also prepared problems that were ultimately not used in this round.
• lkrqwq for optimizing many details of problems.
• StarSilk and errorgorn for black red testing.
• Network_Error, StelIawinD, _istil, jiazhichen844, ETO_leader, Dragos, MtSaka, Caylex, nifeshe, rolandpetrean for red testing.
• Proof_by_QED, lkrqwq, Watersphere, Timosh, tzl_Dedicatus545, 0x0002, a_little_cute, morandyg, abruce, programpiggy for yellow testing.
• MornStar, Ns6Juruo for purple testing.
• cybher, zhouyitao123, Nyemot, Pie_TealCompressorDragon for blue testing.
• xiaohaoaibiancheng666 for cyan testing.
• NSZBD_dklmq_12 for green testing.
• NanguX for gray testing.
• MikeMirzayanov and KAN for the great Codeforces and Polygon platforms.
• You for participating in this round.

Scoring Distribution:

Good Luck & Have Fun!

UPD: Editorial has been posted

Hi everyone!

The OCPC (Osijek Competitive Programming Camp), an award-winning camp for university students preparing for ICPC and other coding competitions, is back this Summer 2026 — this time with two onsite editions:

• Hong Kong — 8–16 August 2026, hosted at the City University of Hong Kong.
• Iași, Romania — 12–20 September 2026, hosted at Alexandru Ioan Cuza University of Iași.

Both editions are organized by us together with local hosts at each site, and use the same contest set — so you take part in one of them. As a rough guide, the Iași edition is most convenient for teams based in Europe, and Hong Kong for teams in APAC and East Asia — but you are welcome at whichever you prefer. The camp is inspired by the competitive programming camps we attended during our active ICPC years: 7 ICPC-style contests (5 hours, 9–12 problems each), with analysis sessions and days off in between.

Please use this form to register for the camp!

Hong Kong — August 2026

• Venue: City University of Hong Kong, Kowloon Tong, Hong Kong.
• Onsite hosts: Minming Li and Yixiong (City University of Hong Kong).
• Exact dates: 8–16 August 2026. Expected start time 10:00 HKT.
• Accommodation: We recommend using on-campus CityUHK Lodge (you can request reservation in the registration form).

Participation free is completely waived for in-person teams of this site!

Iași, Romania — September 2026

• Venue: Faculty of Computer Science, Alexandru Ioan Cuza University of Iași.
• Onsite host: Juve45 (Alexandru Ioniță, UAIC Iași).
• Exact dates: 12–20 September 2026. Expected start time 10:00 EEST.

Hello / Selamat sejahtera / 你好 Codeforces!

Crochet penguin plushie,
credits to gry3125

We, quacksaysduck and _ja are excited to invite you to Order Capital Round 2 (Codeforces Round 1104, Div. 1 + Div. 2), which will start on Jun/18/2026 17:35 (Moscow time)! In this round, you will help Ja the Ghost and Quack the Duck on their daily shenanigans.

This round will be in the format of an IMO mock. There will be $$$9$$$ problems which you will have to solve in $$$3$$$ hours. This round will be combined for Division 1 and Division 2 and will be rated for everyone. Please note that this contest contains at least one run-twice problem, so please read the guide for run-twice problems if you are unfamiliar with them.

All problems in this round were authored by quacksaysduck, _ja, StarSilk and zeemanz.

We would like to thank the following people for their contributions:

• Sugar_fan for his coordination and advice,
• Um_nik for preliminary review,
• Boboge for carrying the problem preparations,
• StarSilk and __baozii__ for providing some cool problems,
• Alexdat2000 for translating statements into Russian,
• _ja, Mitsukasa_Ayase, geospiza, leg, EvenImage, fallleaves01, Tobo, Code937, Boboge, Erica_aaa, andreumat, SSerxhs, Timmyliuyunxi, gongkoufadongji, chyragym, Misumi_Ichika, Syuzi777, __baozii__, _LeMur_, turkhuu622, oToToT, vito1036, FelixArg, SUL, marianoferesin, GILGAMESH, The_Lion_King_777, Hile_Meow, Sakuya_maid, edogawa_something, tiger2005, shendeliliang, Arpa, SergeiFedorov, -XraY-, VadymKa, scorpion, surokpro, lIlIlIlIIll, Buek for testing and providing valuable suggestions,
• MikeMirzayanov and KAN for the amazing Codeforces and Polygon platforms,
• and lastly, You for participating.

The score distribution:

Fun fact: As far as Evirir knows, this is the second round by Malaysians since 2020!

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

👋Hello Codeforces!

I’m Igor -XraY-, CEO at Order Capital. Last year we ran our first Codeforces round and were genuinely impressed by the community response! So we’re happy to be back with Order Capital Round 2🚀.

We’ve prepared a fresh set of problems with interesting ideas and a few surprises along the way. Whether you’re here to push ratings, enjoy a good contest, or just vibe with interesting problems, jump in.

💸Just like last year, we’ll have prizes and some awesome merch for top performers as well as a few randomly selected participants.

Prizes

• 🥇 🥈 🥉 🎖 1–4 — 1000 USDT
• 5 — 800 USDT
• 6 — 700 USDT
• 7 — 600 USDT
• 8 — 400 USDT
• 9 — 300 USDT
• 10 — 200 USDT

🎁 PLUS:

Top 10 + 20 randomly selected participants ranked between 11 and 200 will get our secret Order Capital merch boxes 🎁

At Order Capital we are constantly developing and looking for talented ambitious people to join our team. Hit the button below to check out the career opportunities in Order Capital.

Enjoy the contest, have fun solving, and we hope to see your name near the top of the standings!

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

UPD: Editorial is up.

Hello CodeForces!

ICPC just announced Europe Women's Programming Contest 2026 — an individual algorithmic programming contest for women and non-binary students across Europe. Online qualification is on July 4, and top 20 contestants advance to the onsite finals in Stockholm on August 21-24!

Registration is open on ewpc.icpc.global.

See you there!

👋Yo Codeforces!

Hello from Order Capital!

Last year we launched our very first Codeforces contest and the response was way beyond our expectations.

So we had no choice but to run it back!

For those who don’t know us yet:

Order Capital is a group of companies specializing in software development and automated trading. We combine modern technology and research to make data-driven decisions in quantitative trading and explore new opportunities for business growth.

🚀 Introducing: Order Capital Round 2 (Codeforces Round 1104, Div. 1 + Div. 2).

This time we’ve prepared:

• a new set of problems;

• plenty of interesting ideas;

• a few unexpected twists.

Whether you're aiming for a new rating milestone, looking for a good challenge, or simply enjoy solving well-crafted problems, we'd love to see you on the leaderboard.

Competitive programming is a huge part of our culture, and organizing this round is our way of giving back to the community that continues to inspire us every day.

💸 Prizes

• 🥇 🥈 🥉 🎖 1–4 — 1000 USDT
• 5 — 800 USDT
• 6 — 700 USDT
• 7 — 600 USDT
• 8 — 400 USDT
• 9 — 300 USDT
• 10 — 200 USDT

🎁 PLUS:

Top 10 + 20 randomly selected participants ranked between 11 and 200 will get our secret Order Capital merch boxes 🎁

We’re keeping the tradition alive just like last year, there will be something fun and unexpected inside 👀

And here’s a little throwback to what we had last time to set the mood 📸

We are growing and have open positions in Dubai and (drumroll 🥁) Amsterdam — yes, we’re opening a new office and hiring onsite in both locations.

We’re looking for:

• C++ Engineers (low-latency, high-performance)
• ML Infra Engineers (Python / C++)
• Research Engineers with strong algorithmic skills

🎯 What drives us:

• Solving hard Olympiad-level problems
• Open discussion and exchange of ideas
• A culture built around engineering, not process

Curious about Order Capital? Just fill out a quick form.

Big shoutout to the Codeforces team + everyone who stress-tested these problems.

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

Good luck and have fun in Order Capital Round 2!

— Team Order Capital

Шумбрат, Сәлам, Привет Codeforces!

We are pleased to invite you to participate in Codeforces Round 1103 (Div. 3) on Jun/12/2026 17:35 (Moscow time) — another Codeforces round for third division. You will be given 7-8 problems, which were prepared to create an interesting competition for participants with a rating 1599 or lower. However, those with a rating 1600 or higher can register for the round unrated.

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. We tried our best to make reliable tests — just like you, we will be very disappointed if many participants' solutions are hacked after the ending of the contest.

You will be given 7-8 tasks for 2 hours and 30 minutes to complete them.

Note that the penalty for the wrong submission in this round is 10 minutes.

Remember 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)
• do not have a point of 1900 or higher in the rating.

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.

Problems have been created and written by arsen1y, dvb1r and me.

We would like to thank:

• Vladosiya for excellent coordination.

• Friendiks and Treks for red testing.

• sqwiijqk, Arpa, Fakewave, sahasrad, yanb0, Egorsa and absolut3 for yellow testing.

• SapeginIgor, ElyesChaabouni and D_ck for purple testing.

• _bourrasque_, sh1n0a, OrleanMagic, string_eureka, stepan1111, BankaVarenya, Egorzykin, itz_pabloo, Timiguro, Datym, Ferume and ixeteny for blue testing.

• opa, WiseKid, furt1ve and Gordey_Leushin for cyan testing.

• KruPavel, mrskzv, HelloFromMars, mhmusanna, Chaynikov, Gosha2403, hsiFomeN and Everes for green testing.

• ilyamn22 for grey testing.

• MikeMirzayanov и KAN for Polygon and Codeforces platforms.

• And, of corse, thanks a lot You for participating!

P.S. try to match the authors in the following photo!

UPD. Editorial is posted!

Hello Codeforces!

The series of Educational Rounds continues thanks to the support of the Neapolis University Pafos.

On Jun/09/2026 17:35 (Moscow time) Educational Codeforces Round 191 (Rated for Div. 2) will start.

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 or 7 or 67 problems and 2 hours to solve them.

The problems were invented and prepared by Ivan BledDest Androsov and me. Also, huge thanks to Mike MikeMirzayanov Mirzayanov for great systems Polygon and Codeforces.

We would also like to express our gratitude to the problem testers: ashmelev, awoo, FairyWinx, Alenochka, basalov_yurij, robotolev, dariasaligina, Matrosk1n, Fucking_Specialist, Ya-chmen, Loller4ik, adedalic, shnirelman, pusheen_1024, _OCHEPYATKA_, paomur, nik1998, fisym, Galina_Basalova. Thank you for helping us prepare the contest!

Our friends at Neapolis University Pafos have a final, urgent message:

LAST CHANCE: Only 2 Days Left to Apply for CSAI!

The final admission round for the BSc in Computer Science and Artificial Intelligence at Neapolis University Pafos closes the day after tomorrow.

Final Application Deadline: June 9, 2026.

Don't miss your chance to apply for one of up to 40 JetBrains Foundation Scholarships covering:

• full tuition

• accommodation

• monthly stipend

• visa support

Start your application now and secure your place! The Mandatory Entrance Test is scheduled for June 14, 2026.

Good luck to all the participants!

UPD: Editorial

Hello, Codeforces!

We are excited and pleased to announce that Codeforces Round 1102 (Div. 2) will be held on Jun/07/2026 17:35 (Moscow time). This round will be rated for all participants with rating below $$$2100$$$. You will be given $$$2$$$ hours and $$$15$$$ minutes to solve $$$6$$$ problems, including one split into two subtasks (not necessarily placed adjacently).

All problems were authored and prepared by Fakewave, FairyWinx and me.

We would like to express our special thanks to:

• FairyWinx for awesome coordination;
• 300iq, k1r1t0, _istil, Wansur, and __baozii__ for red testing.
• _Crimson_, Ansori, and Arpa for orange testing.
• VitaliiV, sanya37y, and pattern-seeker for purple testing.
• pokysayou, eyfxrby, katya_prints, AK_15, Morselllprimo, and alex_step for blue testing.
• nik_exists, s97b, opa, AbramovAndrey, furt1ve, and Re06741math for cyan testing.
• ak1ko, Everes, and re06769 for green testing.
• bibiq, Yanemilashkarr, and re067 for gray testing.
• MikeMirzayanov and KAN for the great platforms Codeforces and Polygon.
• And last but not least, You for participating!

The score distribution is below.

GLHF!

UPD: Editorial!