Hello everyone!

I am an author of problems of today round. This round is for both divisions. There will be 7 problems, the first 5 of them are for the second division and the last 5 are for the first one.

About points of problems. Today they are nonstandard:
for div2: 500-1000-1500-2000-2000
for div1: 500-1000-1000-1500-2500
Be careful.

RAD helped me for preparing the round. Delinur translated statements into English.

Good luck ans have fun.

UPD.
 winners of the first division
1. peter50216
2. tourist
3. ACRush

winners of the second division
1. iamcs1983
2. zyx3d
3. seanwupi

Editorial.

UPD.
Unfortunately, in author's solution of priblem E some bug was found. We thanks participant LinesPrower for detection of it. Author's solution was updated and all solutions were rejudjed. Ratings will be recalculated for all participants excluding Egor and Jacob. We apologize for this incident.

The first information letter

General information

From 1nd to 11th August 2011 Saratov State University runs an international student summer school in computer programming. Teams of three people and individual participants are invited to take part in it.

The school will take place in a picturesque place at one of Saratov resort centers on the Volga bank. The participants will be provided comfortable rooms for 2-4 people and meals three times a day. The resort center owns a beach and sport grounds.

It will be 10 training days. The school includes lectures by Saratov state university coaches, joint trainings, problems tutorials and topical workshops. The curriculum is designed for younger university students who aspire to achieve high results at programming competitions. Official language — Russian.

The fees are 16000 RUR (~ 570 USD) for a person. Moreover, each team or an individual participant should bring a laptop with the support of WI-FI.

All interested participants and teams should register at http://acm.sgu.ru/sazanka-2011/ till 20th June 2011. Don't postpone the registration, as the number of participants we can take is limited.

You can get additional information by e-mail mirzayanovmr[symbol-at]gmail.com. As since the official language of the school is Russian, the registration requires knowledge of Russian. Also it is recommended to view this page in Russian.

About Saratov State University

Saratov State University, regularly achieves significant advances in programming competitions. The following are the main achievements of the university in international competitions:

• 2002 ACM-ICPC World Finals silver medals, Europian Champions
• 2003 ACM-ICPC World Finals silver medals
• 2006 ACM-ICPC World Finals golden medals, Europian Champions, World Champions
• 2007 ACM-ICPC World Finals silver medals
• 2009 ACM-ICPC World Finals golden medals
• 2010 ACM-ICPC World Finals silver medals
• 2011 ACM-ICPC World Finals silver medals

Hello!

I remind you that tomorrow will be ACM-ICPC World Finals Contest which will begin at 13:00 (UTC). The live results probably will be available by the links: http://zibada.ru/finals/ or http://icpc.baylor.edu/.

Watch! Ail! Share your impressions!

On May, 25 in the evening we attended a dinner show called "Treasure Tavern". Dinner combined with show is a rather popular entertainment format here. There were several variants and we chose this as the least childish one. In fact, the show combined elements of a stand-up comedy, a musical and a circus. It all was spiced up with the entourage of a kind of a cabaret tavern with waitresses in short dresses. However, apart from a dosen of vulgar jokes the tavern theme didn't develop. During the show we didn't understand lots of stuff, but the artists' performance was on the top level. We were impressed by a dancing couple, where the woman was sometimes hidden for literally a second behind a special curtain and the next moment she appeared in a new garment. The gymnasts' performance was also on the top level. We weren't particularly impressed by the food, but on the plus side, it was the first time I've tasted meat with blood and I liked it. On our way home Artem even went to Burger King (I understand him).

The performers tried to make a superstar out of Kolya but he refused

The train number nine from Saratov to Moscow was a pleasant surprise. Every compartment in our wagon had a small TV, outlets, and each passenger could use a personal safe with a code lock. Of course, we didn't turn the TV on and didn't use the safes. Imagine how ironic it would be if we put there, say, a passport and forgot the code number.

Note that there's not only a TV, but also also outlets behind Nickolay.

In Moscow we had a little snack in some seedy railway eatery (in fact, Kolya and Artem went to Mcdonalds) and got on an express to the Domodedovo Airport. The fun lasted 40 minutes and cost 12 USD rubles each. Russian Railways have a good business!

Today Saratov delegation will go to the championship's finals. As you remember, we've been planning to go to Sharm El-Sheikh since January, watching their great February revolution anxiously. As a result, the finals were moved to Orlando (Florida, USA). Our delegation got a little smaller too, as May is a hot month and it's a long way from Russia to the USA.

Our team is famous on Codeforces. And that's not surprising! Just look at them:

• Maxim Ivanov (e-maxx) spends considerable time among the top rated users and among the top contributors. Many know his wonderful site http://e-maxx.ru/, of course. Attentive users recognize him as a determined bug filer in gcc issue tracker and an author of some contests. Maxim is on the fifth year in SSU Mechanics and Mathematics Department and his interests include "programming, programming and... oh yeah, programming :), zen, taoism, philosophy, psychology, the bike".
• Artem Rakhov (RAD) is known as the Codeforces problems' coordinator, the participant of all on-site prestigious competitions (TopCoder Open, Google Code Jam, Faceboook Hacker Cup) and a great Cola fan. Personally, I've known Artem since the eight year at school and I shudder to think how many problems he has solved since then :)
• Nikolay Kuznetsov (NALP) is known as the author of several rounds and the one who fights ardently for clear statements. He used to be in one team with Artem back at school days. I remember how surprised I was when I learned that he got to TopCoder High School Competition. Nikolay is a third-year student of the Department of Computer Science and Informational Technologies of SSU and he is my student. On July, 10 I exam him on the theoretical course in Programming Methods. By the way, Kolya, let me remind you that you haven't yet got the pass for the practical work!

Besides, the team has me as the coach and Antonina Fedorova as the team leader.

I will do my best to keep you up to date on how the trip's going (mostly on the actual finals, of course). However:

I urge the participants of the event not to keep their interesting impressions hidden and bottled up. I want you to share them. For example, you can publish them on Codeforces!

As a conclusion to the entry, I want to ask a question to those who have already planned the whole trip. As far as I understand, the couple of days before the finals in Orlando won't be spent uselessly: there are some grand amusement parks around. I've got a question to those who are prepared and to those who are keen on that: which place will be most interesting for the ACM-ICPC team? As far as I understand, the tickets to those parks are not exactly cheap, but in one can get a discount now and then - how should we purchase the tickets?

Just in case I inform the Saratov residents that we leave today, on May 23, on train 9.

Hello, dear participants and spectators!

Let me remind you that the elimination phase of the open programming competition "Yandex.Algorithm" comes to an end. With it this means that the time for the most important event of the phase has come: the elimination round for the finals (finals will be held at the Yandex Summer School)! This means that today two hundred best participants of the tournament (based on the results of the previous qualification rounds) will compete to get into the top-15 of the world olympiad programming community.

We hope that the round will be appreciated not only by the participants but also by the spectators, who will have the opportinity to watch the events developing for at least two hours.

Please, pay attention to the problems' costs: 500, 1000, 2000, 2500, 2500. I also advise you to read all the statements, as the choice of the costs and the order is certainly subjective.

Round will be rated for all the participants (including those competing hors concours).
Good luck to the participants. The problems are going to be rather hard, so you'll have to do your best!

I also wish a spectacular round to the rest!

Round is over. According to the results, 20 participants solved at least three problems, and just one (the winner) was able to solve the fourth. The first three places were taken by Petr Mitrichev, Gennady Korotkevich and Sergey Kopeliovich. Congratulations!

In addition to this, 15 leaders advanced to the finals: Petr, tourist, Burunduk1, ivan.metelsky, dzhulgakov, e-maxx, LayCurse, rng_58, pieguy, zeliboba, ktuan, levlam, wata, dolphinigle, Progger .

Problems proved to be rather tough. Here's the full analysis.

We are glad to welcome all contestants of a qualifying contest "Yandex.Algorithm 2011 - Round 1".

Today's round authors are Vitaly Goldshteyn, Ignat Kolesnichenko, Stanislav Pak and Denis Yarets. All we are employees or interns of Yandex. We really appreciate Artem Rakhov, Maria Belova and Mike Mirzayanov who helped us to prepare the contest. We hope that our tasks will be quite interesting and you will get much fun solving them.

As you may know top 200 contestants after this round will be able to continue fighting for spots in the final round.

Please pay attention that as well as during the previous qualifying round Codeforces functionality will be a little cut down for the time of the competition. Do not worry, all will return into place after the end of the round.

Round will be rated for the official participants, and for those who failed to qualify and participate out of competition (unofficial).

Welcome to Codeforces Beta Round #72.