In Codeforces Round 953 (Div. 2), the account Teddiursa was used by more than one person at the same time, and they worked as a team to solve the problems. The participation of this user was unrated for punishment. So does it mean that two people using two different accounts submitting similar codes should be skipped, but if they use the same account, they will only be unrated? Why is there a difference?

I know many people think the problems are bad and want the contest unrated. I lost GM from this round too. But I think the problems are somehow ok. FSTs on A is avoidable, and using long long is actually very obvious. More low rated users FSTed than high rated users, so this is ok and I consider it as part of the problem. BCDEF are good(though I didn't solve E, and also I ignored m<=5000 in F). I know the std for G was wrong at first, but it's fixed quickly, which isn't a big problem. H would also be a good problem, if there isn't oeis. I noticed that many people had passed H when I was doing E, so I tried H in the last 1h. I nearly got the formula in the contest.

Though I still think that authors should at least try to check on oeis before having problems like this, and they should also check for integer overflows for every problem.

Hope to reach GM soon and good luck for everyone :)

I was reading the announcement for ABC332 by atcoder_official and I clicked into this account. This account has a contribution of +134 and it's still rising. Soon it will come to the top 10 contributors. Maybe we should remove it from the contribution ranklist, for example making it Headquarters.

I think Codeforces should add a new tag to the problemset called corner cases for problems that have many corner cases or many participants FSTed or got hacked on. This can let other people know they should check their codes carefully before submitting.

Examples: 1801B - Buying gifts and 1811F - Is It Flower?

You can write some of the problems you got hacked on in the comments, and I'd like to try them.