A_Ringer and 2021csb1073 I saw this comment today- https://codeforces.com/blog/entry/64993?#comment-981388

I wondered why someone would need two accounts during the same contest. So, I decided to check their contest history. I found out that they have a lot of contests in common with similar rankings and even their rating graphs overlap. I decided to check a random solution in both of these accounts, 172724238 and 172727633 are exactly the same line by line if not for the clever tricks used by them to confuse the plagiarism checker. The timeline of the submissions also overlap.

I request the moderators and admins to take appropriate action against such people.

Below is a type of comment added to fool the checker -