I am glad to invite you to participate in Codeforces Beta Round #52 (Div. 2). Today's round was prepared Michael Mirzayanov, Max Ivanov and Maria Belov.
It's possible that "out of the competition"-participants will not be able to use the tab "hacks". Do not panic, on the next Div. 2 Round we will necessarily fix it.
Artem Rakhov and Codeforces team