I was participating in recent Round #574 (Div. 2) contest (and not really successfully :D) and was monitoring submissions/standings. What I wonder is: how do some red and other people send their complete solutions to a problem on 2nd or 3rd minute? Do they have access to the tasks before the contest? Or it's some special mode of participation or something? I need 2 minutes just to read the task and open the editor, and they finish it in that time?

Thanks in advance.