Unusual tournament Manthan 2011 showed the weaknesses of the current rating formulas. After the end of contest the winner of the competition tourist has expected rating change equal to "-1":)

This has arisen due to reduction of the calculated changes in such a way, that total sum is equal to 0. That is, Gennady was in some pros before such changes, but as the sum of all the changes turned out to be positive, then all the ratings were a little reduced. As a quick dirty hack in the round I turned off this feature, leading to a one-time inflation. Even a small mistake: I noticed that participants in the second division get too many points after a good performance on "Div. 2 Only" rounds.

I'm glad to see you on Codeforces Beta Round # 64.

Today I am the author of the tasks. I'm a student of Tyumen State University.

I want to thank all those who helped me to prepare the round: Nikita Durynin (Austeritas) for the pair ideas for the tasks, Dmitry Bochkarev (Walrus) and Chernenkov Alexey (Laise) for the testing, Artem Rakhov (RAD) for coordinating the activities, Maria Belova for translating and Mike Mirzayanov (MikeMirzayanov) for a great system.

Today you will visit the Walrusland and help the common citizens and government to solve their problems.

Good luck for everybody, let the best man win!

Winner is Petr. Congratulations!

Analysis

Hello!

Today I am the author of all tasks. At the contest you will be asked to help students from Chelyabinsk in solving their non-trivial problems.

I want to thank all those who helped me to prepare the round: Anton Garder for his invaluable assistance in the preparation of sets of tasks, Demid Kucherenko for assistance in the preparation of conditions, Artem Rakhov for coordinating the activities and patience J, Maria Belova for translating and  Mike Mirzayanov for a great system.

 Good luck!

Winner - Solo

Analysis - http://mirror.codeforces.com/blog/entry/1571

Hi all!

Unknown language round #1 was up, 21st of February and now we're going to hold yet another Unknown language round.

It will be the usual ACM-ICPC unrated contest , so there is no hacking! The only feature - you will be able to submit problems using the only one, not very popular language. What? It's a secret! And I expect you'll have to learn the language at the time of contest since the used language will be a secret until ~1 minute before the start of contest.

Problem setters of this round are Alireza Farhadi, Saeed Ilchi, Sajjad Ghahramanpour, Zahra Rohanifar and Me. We are extremely grateful to Mike Mirzayanov and Artem Rakhov.

Number of problems will be more than usual and the problems concentrate on coding abilities rather than algorithmic view and problem solving techniques.

UPD:The contest is over

Congratulations to the top 3 winners who solved all problems:

Wrong

tomek

watashi

Google Sponsored event with Prizes worth 50,000 INR. Besides, Certificates to top 50 participants. Event Details:

• The main event is scheduled on March 13 at 2200 Hrs IST (UTC+5:30)
• Rules of contest similar to Codeforces Beta Rounds.
• The Contest will be of 3 hours consisting of 5-6 problems.
• Programing languages allowed: C, C++ , Pascal, Java, C#, Python, Ruby, PHP, F# and Haskell.
Open to all, students as well as professionals.
Declaration of Results on March 16 at 1800 Hrs IST.

Note: Contest duration has been reduced from 4 to 3 hours.

Visit the Manthan event page for further details of the contest.

The contest duration changed to be 3 hours. Good luck!

Last night I don’t want to sleep, so – I was working. I reread my old post "Contribution 2.0" (in Russian) and decided to implement some ideas. Taking into account the comments that everyone (no matter the color nor the position in the contribution) has the right to express their opinions in the form of pluses or minuses, I did not restrict users the opportunity to express opinion.

On the other hand, the rules of contribution changing depending on your votes have modified. Since we have already appeared bots, trolls and other vermin, I will not reveal details, but note that:

• Contribution may change after some time after the processing of your vote - it is normal.
• Not all your votes may be taken into account when calculating the contribution changing - this is also normal, we will defend ourselves from dirty tricks.
• contribution slightly scaled - the numbers got bigger. Maybe it's nicer?

Just want to say that the bots usage, following the principles of "blood feuds," etc. serve as a reason for your disqualification. Do not tempt fate.

Soon, the problems coordinator, the user RAD will leave official lists of both contributions and rated, as he is active member of the Codeforces team.

I wish you high contribution
MikeMirzayanov