Hi to all!
A few hours later you're lucky to participate in Codeforces Round #159 for Div.2 participants, but traditionally the others can take part out of the competition. It has been prepared by me (NALP), Ivan Fefer (Fefer_Ivan), Pavel Holkin (HolkinPV), Vitaly Aksenov (Aksenov239) 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!
UPD: Today it is decided to use dynamic scoring system. But the problems will be sorted from low difficulty to high by authors' opinion!
UPD: The contest finishes, congratulations to the winners!