This round will start Yandex.Algorithm 2011. The problems of the round were prepared by me, of course, with the help of the Codeforces team and Yandex.
I hope you enjoy the problems and their solution will start a successful performance at the tournament.
As you have already noticed — the system operates in a somewhat truncated form. We decided to run it in safe mode and turn off some functionality at the time of the contest. After the round everything will be back.
I recall that the top 500 participants will receive a ticket to the first online round of the Yandex.Algorithm. However, if you do not get to qualify at this time, do not despair — you can participate in the second qualification, which will be held on May 6 at 15:00 (UTC).
I wish you have a fun,