I am writing to document a pattern of behavior by the user tuanha that I believe merits careful review. My intention is not to make accusations beyond the available evidence, but rather to present observations that I believe are sufficiently unusual to justify an independent investigation by the Codeforces team.

The primary concerns include:

A pattern of contest performance that appears inconsistent with prior history. Statistical indicators that, in my view, are unusual enough to warrant further examination. Additional observations that I have collected and can provide upon request, including supporting graphs and contest data.

I understand that none of these observations alone prove misconduct. I also recognize that exceptional improvement is possible through legitimate effort. For that reason, I respectfully ask that the administration evaluate the available evidence using whatever internal tools, logs, and information are available to you.

I would also like to mention that I currently live in Albania. I include this only because I would appreciate that any investigation be handled confidentially and that my identity not be unnecessarily disclosed. I have no desire for public conflict and simply wish to report what I believe should be reviewed.

Thank you for your time and for your continued efforts to maintain the integrity of Codeforces competitions.