Welcome to Codeforces Beta Round #84! I am Vitaliy Herasimov (witua) and I am an author of today's problems. Thanks to Artem Rakhov (RAD) and Pavel Kuznetsov (it4.kp) for the help and advices in preparing of the rounds, Maria Belova (Delinur) for the statements translation.
Contest is over! Congratulation to winners!