A few hours later you're lucky to participate in Codeforces Round #147 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), Pavlik Holkin (HolkinPV), Gerald Agapov (Gerald), 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 has ended, congratulations to the winners: