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