Hi to all!
A few hours later you're lucky to participate in Codeforces Round #149 for Div.2 participants, but traditionally the others can take part out of the competition. It has been prepared by me (NALP), Igor Kudryashov (Igor_Kudryashov), Pavel Holkin (HolkinPV) and Gerald Agapov (Gerald). Also we express thanks to Mary Belova (Delinur) and Mike Mirzayanov (MikeMirzayanov).
Traditionally I wish good luck, accepted solutions and successful hacking attempts for you!
The standart scoring system will be used: 500-1000-1500-2000-2500
UPD: The contest is over, thanks to all!
UPD: Congratulations to the winners:
UPD: the tutorial has been published.