A few hours later, 25 апреля в 19:30 MSK, you are lucky to participate in Codeforces Round #181 for Div. 2 participants. Traditionally, Div. 1 participants can take part out of the competition.
Problems have been prepared by: Gridnev Vitaliy (gridnevvvit), Ignatyev Alexander (ai9128429340875). We want to thank Gerald Agapov(Gerald) for help in preparation of this round, Michael Mirzayanov(MikeMirzayanov) for marvelous Codeforces and Polygon systems, Mary Belova(Delinur) for translating the problems.
About authors: me and Alexander are third year students of Mathematics Department, Saratov State University. It’s our first round and I hope not last.
We hope you will like these problems, and that it will be fun to solve them.
Also we strongly recommend you to read all the problems.
We wish everyone good luck and high rating!
UPD: Scoring will be dynamic. Problems are sorted by increasing order of difficulty.
UPD1: Editorial here
UPD2: Contest finished. Congratulations to winners: