Contest will take place after amount to cover the prize will be collected. In order to take place in the contest you need to write down your sequence number in a comment.
For example, if you are the first person who write a comment, you write "1", the next person writes "2" and so on... So if you see some number in the last comment, you have to wite down the next number (= previous number + 1).
If one number will be written by more than one person, the only person who has written it first will be taken into account.
1
2