Hi!

This Sunday will take place All-Russian olympiad for students of 5-8 grades, in the name of Keldysh. Good luck to all the participants! This contest is prepared by Moscow Olympiad Scientific Committee that you may know by Moscow Team Olympiad, Moscow Olympiad for Young Students, Moscow Open Olympiad in Informatics (rounds 327, 342, 345, 376, 401, 433, 441, 466, 469, 507, 516, 541, 545, 567, 583, 594, 622, 626, 657, 680, 704, 707, 727, 751, 775, 802, 829, 852, 857).

We are happy to announce Codeforces Round 879 (Div. 2) based on the problems of this olympiad! It will be a Div. 2 round, which will take place at Jun/18/2023 11:05 (Moscow time). Please notice the unusual time. You will have 6 problems and 2 hours to solve them.

We kindly ask all the community members that are going to participate in the competition to show sportsmanship by not trying to cheat in any manner, in particular, by trying to figure out problem statements from the onsite participants. If you end up knowing some of the problems of All-Russian olympiad in the name of Keldysh (by participating in it, from some of the onsite contestants or in any other way), please do not participate in the round. We also ask onsite contestants to not discuss problems in public. Failure to comply with any of the rules above may result in a disqualification.

Problems of this competition were prepared by grphil, Mangooste, sevlll777, Siberian, TeaTime, teraqqq, Ziware, TheEvilBird, Ormlis, Alexdat2000, vaaven, Mikhango, Artyom123 guided by Ormlis, grphil and Helen Andreeva.

Thanks to Artyom123 for the round coordination, and also thanks to MikeMirzayanov for systems Codeforces and Polygon, which was used to prepare problems of this olympiad.

Great thanks to the testers of the round: PurpleCrayon, He_Ren, feecIe6418, penguinhacker, ix35, Dominater069, MagicalFlower, tzc_wk, gyh20, ezraft, Kieray, AquaMoon, satori_____, njupt_lyy, Mike4235, ak2006, Lavine, Ritwin, xiaossr, turmax, fastmath, Kapt, Kirill22, Be_dos, Olerinskiy, gmusya, blyat, vsinitsynav, orz, TheGoodest, playerr17, lesssia.

UPD1: Scoring distribution:

500 – 1000 – 1250 – 1750 — 2500 – 3000

Good luck everybody!

UPD2: Editorial