I noticed some bugs caused in today's contest.

First of all, as newmagic mentioned, for some users it didn't start at its own time and contestants simply couldn't enter the contest.
Link to the blog

Another odd thing is that tests for problem A were extermely weak.
After contest i realized that my code was hackable, as i didn't consider that elements ain't distinct, so i basically wrote just a small test which hacked my own solution.
348904721

I was going to hit new max rating, however due to this tiny issue, it's all over :((