Hello!

Right now happens the first tour of the Open Olympiad in Informatics, and tomorrow will be the second one. This contest is prepared by Moscow Olympiad Scientific Committee that you may know by Moscow Team Olympiad, Moscow Olympiad for Young Students and Metropolises Olympiad (rounds 327, 342, 345, 376, 401, 433, 441, 466, 469, 507, 516, 541, 545, 567, 583, 594, 622).

Open Olympiad consists of the most interesting and hard problems that are proposed by a wide community of authors, so we decided to conduct a Codeforces regular round based on it, which will happen on Mar/07/2020 12:35 (Moscow time) and will be based on both days of the Olympiad. Each division 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 Moscow Open Olympiad (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 meshanya, cdkrot, wrg0ababd, vintage_Vlad_Makeev, DebNatkh, diko, voidmax, okwedook, ch_egor, V--o_o--V, Sender, grphil, mingaleg, KiKoS, Endagorion, budalnik guided by cdkrot, ch_egor, vintage_Vlad_Makeev, GlebsHP, Zlobober and Helen Andreeva.

Problems for second division were prepared by vintage_Vlad_Makeev, ch_egor and MikeMirzayanov, to who we also want to say thanks for the Codeforces and Polygon systems.

Good luck everybody!

UPD1:

The scoring distribution for both divisions is standard: 500 — 1000 — 1500 — 2000 — 2500 — 3000

Due to the official competition source codes of other participants will not be available for an hour after the end of the round.

UPD2: Editorial

UPD3: Winners!

Div. 1:

1. zhouyuyang
2. Egor
3. Rewinding
4. mayaohua2003
5. gtrhetr

Div. 2:

1. Tutituti
2. autoint
3. Froggay
4. WWLDX
5. GMaster

Besides the editorial we prepared some challenges for you.

(Idea — MikeMirzayanov, developing — fcspartakm)

(Idea — meshanya, developing — Zlobober, KAN)

(Idea — Zlobober, developing — ch_egor)

(Idea and developng — Sender)

(Idea — V--o_o--V, developer — Flyrise)

(Idea — Sender, developer — cdkrot)

(Idea — Zlobober, developer — malcolm)

(Idea and developng — vintage_Vlad_Makeev)

Hi all!

This weekend, at 14:05 UTC on December 23rd we will hold Codeforces Round 454. It is based on problems of Technocup 2018 Elimination Round 4 that will be held at the same time.

Technocup is a major olympiad for Russian-speaking high-school students, so if you fall into this category, please register at Technocup 2018 website and take part in the Elimination Round.

I would like to thank veschii_nevstrui, adamant and DPR-pavlin who authored and prepared problems for Technocup and ifsmirnov, Kostroma, winger, AlexFetisov, 300iq for testing the round.

Div. 1 and Div.2 editions are open and rated for everyone. Register and enjoy the contests!

Congratulations to the winners!

Technocup:

1. ---------

2. I_love_Palindromic_Tree

3. iakovlev.zakhar

4. IsmagilS

5. DCNick3

Div. 1:

1. jqdai0815

2. Radewoosh

3. Swistakk

4. Um_nik

5. consecutivelimit

Div. 2:

1. Kammola

2. ehnryx

3. LifeCracker

4. emoairx

5. laofudasuanbaofushehui

UPD: Editorial

(Idea — Jury of the Olympiad, developing — Andreikkaa)

(Idea and developing — Kniaz)

(Idea and developing — Sender)

(Idea — glebushka98, developing — ch_egor)

(Idea — GlebsHP, developing — Flyrise)

(Idea and developing — mingaleg)

(Idea — Endagorion, developing — kraskevich)

(Idea and developing — wilwell)

(Idea — Sender , developing — timgaripov)

(Idea — Chmel_Tolstiy, developing — mingaleg)

(Idea — Zlobober, developing — halin.george)

(Idea — GlebsHP, developing — mingaleg)

(Idea — glebushka98, developing — vintage_Vlad_Makeev)

(Idea — Elena Andreeva, developing — vintage_Vlad_Makeev)

(Idea — Zlobober, developing — malcolm)