Codeforces Round #320 [Bayan Thanks-Round]
Difference between en16 and en17, changed 75 character(s)
Hello, everyone! Codeforces Round #320 will be held at [Sep/16/2015 18:00 MSK](http://timeanddate.com/worldclock/fixedtime.html?day=16&month=9&year=2015&hour=18&min=0&sec=0&p1=166). Note that round **starts in the unusual time**!↵

The problems are from [user:tmt514,2015-09-15], [user:shik,2015-09-15], [user:drazil,2015-09-15], and me([user:dreamoon,2015-09-15]). Also we want to thank [user:Zlobober,2015-09-15] for helping us preparing the round,  [user:AlexFetisov,2015-09-15] and [user:winger,2015-09-15] for testing this round , [user:delinur,2015-09-15] for translating the statement into Russian, and [user:MikeMirzayanov,2015-09-15] for Codeforces and Polygon.↵

This is my second time organizing a problemset for a Codeforces round (my previous round: [#292](http://codeforces.me/blog/entry/16446)). In my previous round all problems were provided by me. But I think that if problems are provided by more people, then the contest will be more interesting! So I asked my friends to help me this time. Hope everybody can have fun during the round!↵

Participants in each division will be given **six tasks** and **two and a half hours** for solving them (the last four problems in Div. 2 are as same as as the first four problems in Div. 1). Scoring system will be announced later closer to the start of the round.↵

Bayan is an Iranian software company working on large-scale web applications. It doesn't only↵
develop the search engine, but also it holds an annual open competition <a href="http://contest.bayan.ir/en/">Bayan Programming Contest</a>↵
with an on-site round in Tehran. The on-site round of 2015 became an international event↵
with many strong participants.↵

Bayan has supported Codeforces on our Codeforces 5-year crowdfunding program. Thank you Bayan!↵
This round is in your honor!↵

**UPD 1**: Due to technical reasons the round starts at [18:15 Moscow time](http://www.timeanddate.com/worldclock/fixedtime.html?day=16&month=9&year=2015&hour=18&min=15&sec=0&p1=166).↵

**UPD 2**: The round will use the dynamic scoring with 250 points step.


**UPD 3: Problems are ordered according to their supposed difficulty**.

History

 
 
 
 
Revisions
 
 
  Rev. Lang. By When Δ Comment
en19 English dreamoon_love_AA 2015-09-16 21:55:04 73
en18 English dreamoon_love_AA 2015-09-16 21:22:42 247
en17 English dreamoon_love_AA 2015-09-16 18:06:56 75
en16 English dreamoon_love_AA 2015-09-16 18:03:56 75
en15 English dreamoon_love_AA 2015-09-16 17:59:49 4 Tiny change: 'honor!\n\nUPD 1: Due to t' -> 'honor!\n\n**UPD 1**: Due to t'
en14 English dreamoon_love_AA 2015-09-16 17:58:27 109
en13 English dreamoon_love_AA 2015-09-16 17:57:43 72
en12 English dreamoon_love_AA 2015-09-16 09:40:30 18
en11 English dreamoon_love_AA 2015-09-15 23:00:23 0 (published)
en10 English dreamoon_love_AA 2015-09-15 22:59:50 74 (saved to drafts)
en9 English dreamoon_love_AA 2015-09-15 20:40:31 0 (published)
en8 English dreamoon_love_AA 2015-09-15 20:38:59 978
en7 English dreamoon_love_AA 2015-09-15 20:37:16 508 (saved to drafts)
en6 English dreamoon_love_AA 2015-09-15 18:29:25 16
en5 English dreamoon_love_AA 2015-09-15 18:26:56 104
en4 English dreamoon_love_AA 2015-09-15 16:56:55 0 (published)
en3 English dreamoon_love_AA 2015-09-15 16:30:55 139
en2 English dreamoon_love_AA 2015-09-15 01:03:04 16
en1 English dreamoon_love_AA 2015-09-15 00:56:19 1206 Initial revision (saved to drafts)