At Codeforces Round #833 (Div. 2)

There is a case of cheating in the problem B A solution is available during the contest on YouTube https://youtu.be/0x9kKxfqLr8

Matching solutions:- https://mirror.codeforces.com/contest/1748/submission/180650292

https://mirror.codeforces.com/contest/1748/submission/180650184

https://mirror.codeforces.com/contest/1748/submission/180649269

https://mirror.codeforces.com/contest/1748/submission/180646072

https://mirror.codeforces.com/contest/1748/submission/180646346

https://mirror.codeforces.com/contest/1748/submission/180646263

https://mirror.codeforces.com/contest/1748/submission/180646094

https://mirror.codeforces.com/contest/1748/submission/180645940