To avoid retaliation, I am posting from an alt.
Recently, in the VNOI group there is a post exposing cheaters in an onsite provincial contest in Lam Dong. The contest used this problem on Codeforces. The problem was not translated into Vietnamese correctly and it was impossibly hard. https://imgur.com/COnGYrm
However, cheaters still managed to copy rng_58's code and change some variable names. The changed names were ridiculous. You can see the plagiarized solutions here:
This calls into question the integrity of provincial contests in Vietnam. I think contest problems must be original and proctoring must be strict, otherwise competitive programming won't be taken seriously in Vietnam ever again.