Ну вот это бы пояснение мне хочется видеть в таком случае, а не 404. Хотя бы какой-нибудь access-denied.

Problem C was almost identical to this one:
http://petr-mitrichev.blogspot.com/2011/01/solution-to-alternating-jumps-problem.html

BTW, some words about contest itself.

I could not have imagined some years before that in year 2011 such a stupid contest was possible.

Sometimes problems are bad - not original or too easy or too hard. This time they were terrible.

And the contest rules - simply no words.

Не совсем, вроде как все ещё можно начать виртуальный турнир