Codeforces Round #769 (Div. 2)

№	Пользователь	Рейтинг
1	tourist	3993
2	jiangly	3743
3	orzdevinwang	3707
4	Radewoosh	3627
5	jqdai0815	3620
6	Benq	3564
7	Kevin114514	3443
8	ksun48	3434
9	Rewinding	3397
10	Um_nik	3396

№	Пользователь	Вклад
1	cry	167
2	Um_nik	163
3	maomao90	162
3	atcoder_official	162
5	adamant	159
6	-is-this-fft-	158
7	awoo	155
8	TheScrasse	154
9	Dominater069	153
10	djm03178	152

Hi, Codeforces!

Vladithur and I are pleased to invite you to our Codeforces Round 769 (Div. 2), which will be held on 30.01.2022 17:35 (Московское время). This round will be rated for participants with rating lower than 2100.

We would like to express our great gratitude to:

irkstepanov and KAN for ~~not rejecting our tasks~~ excellent coordination of the round and assistance in preparing problems.
Ormlis, antontrygubO_o, generic_placeholder_name, Alexdat2000, Dart-Xeyter, wxhtzdy, sohsoh, glebustim, radal, snowysecret, stevancv, maxverr, Scrubpai, Artem1303, RomkaRS and MaxShch for testing the round and providing useful feedback.
MikeMirzayanov for cool platforms Codeforces and Polygon.

You will have 2 hours to solve 5 problems, one of which is divided into two subtasks.

The scoring distribution is 500 — 1000 — 1500 — 2000 — (1500 — 1500)

We have tried to make clear statements and strong ~~pre~~tests for the problems and hope you will have fun and increase your rating!

Good luck!

Also, we would like to start the trend of evaluating the round's problems. We think it will give valuable feedback to authors and make future contests better. So please, vote for each problem after the round's end.

Problem A

Problem B

Problem C

Problem D

Problem E1

Problem E2

UPD: Editorial is here!

Rev.	Кто	Когда	Δ	Комментарий
ru17	Vladithur	2022-01-30 22:54:24	0	(опубликовано)
en33	Vladithur	2022-01-30 22:53:57	0	(published)
ru16	Vladithur	2022-01-30 22:53:27	433	(сохранено в черновиках)
en32	Vladithur	2022-01-30 22:52:01	445	Tiny change: ':tute7627]\n2. [user:jia' -> ':tute7627] ans [user:jia' (saved to drafts)
ru15	Igorfardoc	2022-01-30 19:37:46	0	(опубликовано)
ru14	Igorfardoc	2022-01-30 19:37:19	65	(сохранено в черновиках)
en31	Igorfardoc	2022-01-30 19:36:34	0	(published)
en30	Igorfardoc	2022-01-30 19:36:05	70	(saved to drafts)
en29	Igorfardoc	2022-01-30 19:25:09	0	(published)
en28	Igorfardoc	2022-01-30 19:20:30	0	(saved to drafts)
en27	Igorfardoc	2022-01-30 19:19:15	74	(published)
en26	Igorfardoc	2022-01-30 19:17:59	74	(saved to drafts)
ru13	Igorfardoc	2022-01-29 01:08:37	4	Мелкая правка: '22-01-28] and [user:KAN' -> '22-01-28] и [user:KAN'
ru12	Igorfardoc	2022-01-29 00:08:15	0	(опубликовано)
en25	Igorfardoc	2022-01-29 00:07:08	0	(published)
ru11	Vladithur	2022-01-28 23:37:13	14	Разбалловка
en24	Vladithur	2022-01-28 23:35:57	14	Changed scoring distribution
ru10	Igorfardoc	2022-01-28 18:42:00	3	Мелкая правка: '022-01-28], [user:Max' -> '022-01-28] и [user:Max'
en23	Igorfardoc	2022-01-28 18:41:45	5	Tiny change: '022-01-28], [user:Max' -> '022-01-28] and [user:Max'
en22	Igorfardoc	2022-01-28 18:38:37	4	Tiny change: 'rejecting all our tasks' -> 'rejecting our tasks'
en21	Igorfardoc	2022-01-28 18:37:33	1	Tiny change: '### Hi, Co' -> '#### Hi, Co'
ru9	Igorfardoc	2022-01-28 18:37:23	1	Мелкая правка: '### Привет' -> '#### Привет'
en20	Igorfardoc	2022-01-28 18:36:03	2	Tiny change: 's end.\n\n\n<spoil' -> 's end.\n\n<spoil'
en19	Igorfardoc	2022-01-28 18:35:43	2	Tiny change: 's end.\n\n<spoil' -> 's end.\n\n\n<spoil'
ru8	Igorfardoc	2022-01-28 18:33:00	17
ru7	Igorfardoc	2022-01-28 18:26:34	11
ru6	Igorfardoc	2022-01-28 18:20:43	71
ru5	Igorfardoc	2022-01-28 18:17:44	5	Мелкая правка: ', что это полезный ' -> ', что это даст полезный '
ru4	Igorfardoc	2022-01-28 18:16:06	73
ru3	Igorfardoc	2022-01-28 18:15:20	106
ru2	Igorfardoc	2022-01-28 18:14:32	1939
ru1	Igorfardoc	2022-01-28 18:02:28	2796	Первая редакция перевода на Русский (сохранено в черновиках)
en18	Vladithur	2022-01-28 17:02:28	82	Tiny change: 'edback to the authors a' -> 'edback to authors a'
en17	Igorfardoc	2022-01-28 16:54:01	1	Tiny change: 'k!\n\nAlso we would ' -> 'k!\n\nAlso, we would '
en16	Igorfardoc	2022-01-28 16:49:24	24	Tiny change: 'Hi, Codeforces!\n------------------\n[user:Vl' -> '### Hi, Codeforces!\n[user:Vl'
en15	Igorfardoc	2022-01-28 16:48:47	922
en14	Igorfardoc	2022-01-28 16:47:22	41
en13	Igorfardoc	2022-01-28 16:43:46	13	Tiny change: 'e authors of the round and it co' -> 'e authors and it co'
en12	Igorfardoc	2022-01-28 16:42:54	46
en11	Igorfardoc	2022-01-28 16:42:05	37
en10	Igorfardoc	2022-01-28 16:41:03	2	Tiny change: 'oblem A.\n\n- Do not' -> 'oblem A.\n- Do not'
en9	Igorfardoc	2022-01-28 16:40:32	24	Tiny change: 't [likes:1,option1]\n- Aver' -> 't [likes:1]\n- Aver'
en8	Igorfardoc	2022-01-28 16:34:51	438	Tiny change: 't (likes:1,option1)\n- Aver' -> 't (likes:1)\n- Aver'
en7	Vladithur	2022-01-28 16:01:57	179
en6	Igorfardoc	2022-01-28 15:42:01	265	Tiny change: 'lear statesments and ' -> 'lear statements and '
en5	Igorfardoc	2022-01-28 15:27:30	8	Tiny change: ' for cool Codeforces' -> ' for cool systemCodeforces'
en4	Igorfardoc	2022-01-28 15:23:22	102
en3	Igorfardoc	2022-01-28 15:14:02	614	Tiny change: 'y], [user:z' -> 'y], [user:sohsoh], [user:z'
en2	Igorfardoc	2022-01-28 14:58:07	320	Tiny change: 'ime:1632].' -> 'ime:1632].\n1234'
en1	Igorfardoc	2022-01-28 14:42:24	204	Initial revision (saved to drafts)

Hi, Codeforces!

История