Good afternoon, friends)
We introduce you Codeforces Round #126 (Div. 2). Please note, Codeforces Round #126 (Div. 2) will be only today and only today you will have unique opportunity to raise your rating in this competition (certainly, you will be able to solve problems virtually after round, but this doesn't change your rating). Also round will be unrated for participants from first division.
This round was prepared by students of Saratov State University: Nicolay Kuznetsov (NALP), Pavel Kholkin (HolkinPV), Igor Kudryashov (Igor_Kudryashov) and Gerald Agapov (Gerald). Also we thank creator of Codeforces Michael Mirzayanov (MikeMirzayanov) for amazing system, member of staff of Codeforces Mary Belova (Delinur) for great translation and Alexander Kuprin (Alex_KPR) for help in preparation of this round.
Note, today it is decided to use dynamic scoring system (Learn more about dynamic problem scoring).
Also problems will be placed in random order, it means they aren't sorted in increasing order of difficulty.
More right ideas and fine solutions to you.
UPD. Competition is over. Thanks for all who participated. We hope you enjoyed the participation, and round not passed in vain. Editorial will be posted soon. Congratulations to the winners: