Hello, Codeforces!

I want to test the system before Good Bye 2016, to be sure that everything works as expected.

I invite you to take part in Testing Round 13. It will start soon, on December, 29, 09:05:00 (UTC). It will be unofficial unrated round.

Pretests are unusually weak to trigger more hack.

You may expect interactive problems. Hope for hacks for them.

Thank you,
MikeMirzayanov