Hello, Codeforces!

I am very excited to invite you to participate in Codeforces Round 1122 (Div. 3), which will take place on Sep/21/2026 17:35 (Moscow time). You will be given $$$2$$$ hours and $$$30$$$ minutes to solve $$$7$$$ or $$$8$$$ problems. All problems were authored and prepared by me, WorldWarV.

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.

You should 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 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 breaking this rule, you will be dropped into cry's basement, which happens to be a permanently active volcano.

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

• cry for spectacular coordination of the round and answering all 998244352 of my questions;
• Edu175, __baozii__ for red testing;
• omsincoconut, CatsAreCool, Edeeva for orange testing;
• wakanda-forever, Argentum47, yse, SpyrosAliv, linearspace for purple testing;
• simplelife, Eikyu, nik_exists, silverkeep, expertaq for blue testing;
• koseitsukamoto for green testing;
• Vladosiya for Russian translations and testing;
• MikeMirzayanov for developing Codeforces and Polygon.

GLHF!