Today, in lots of contests, hacks are unrespected. There are no hacks in 90% of div1 round. However, find someone's mistake is a nice skill. I suggest a hacker contest. 1. There is no score for the problem, only for hacks. 2. You are allowed to copy someone's codes into local. 3. 2 hour solving and 12-hour hacking, like educational codeforces. 3.5. You could hack the problem only if you solved it. 4. No pretests except samples, and no systest either. The only real test would be from hacks. 5. Score is 100*successful hack-50*unsuccessful hack. Of course, the contest should be unrated, because it is hackforces, not codeforces.