Hello! We invite you to participate in Codeforces Round 1125 (Div. 3), which will take place on Oct/07/2026 17:35 (Moscow time).

This will be a Division 3 round. You will be given 8 problems, authored by me and polished to perfection with the help of Noobish_Monk and Gornak40, as well as 2 hours and 30 minutes to solve them.

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.

We remind you that only trusted participants of the third division will be included in the official standings. This is a necessary measure to combat unsporting behavior. To qualify as a trusted participant of the third division, you must:

• have participated in at least five rated rounds (and solved at least one problem in each of them)

• have never had a rating of 1900 or higher.

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).

Note the rule restricting the use of AI. Previous announcements have already tried to scare you, so we will carry on the tradition: if you are caught breaking these rules, you will be sent straight into Gornak40's enclosure with the enraged gorillas.

I would like to thank the following people:

• Gornak40 for coordinating this wonderful round and destroying my long problem statements...

• Noobish_Monk for giving feedback on at least 50 problems before anyone else even got to see this round...

• Kapt, Ormlis for red-and-black testing of the round.

• KseniaShk, cry, snowysecret for yellow testing of the round.

• TheTitan008, Nogaybica, MrKisame for violet testing of the round.

• Mr.Backender, chromate00, OG_Maksimchick4 for blue testing of the round.

• Kolyanchick, Everes, Dan1l0s, Hooded_Hood for cyan testing of the round.

• SqwoM, myav, naakinn, ChernovVladimir for green testing of the round.

• shishko.av, Margaryan_Armina for gray testing of the round.

• zetrock1 for unrated testing.

• Vladosiya for translating the problem statements into Russian wait, the statements were already in Russian. Thank you... for looking over the round and approving it for publication!

• MikeMirzayanov for Codeforces and Polygon.

Good luck!

Once upon a time, photos of the authors were a beloved tradition in Codeforces announcements — so we decided to take a little trip down memory lane.