Hi, everybody, and welcome to the Codeforces Beta Round #9!
I'm its author. :) I've tried to make problems easy to read and funny. I’d like to say thank you to Mike Mirzayanov (for choosing problems for the contest and everything he’s done to organize it), to Igor Kudryashov (for checking author's solutions and making test generators), to Dima Matov (for correcting everything :)) and, of course to Julia Satushina (for excellent translations of the problems’ legends).
I'd like to remind you that if you have any questions on the problems, the best way to ask them is to use the web interface on the problems page.
I believe that the contest will be interesting to you, dear participants! I’m looking forward to seeing your suggestions here.