On the last Codeforces Round 966 (Div. 3) rohan_jena, one of those who completely closed the contest is obviously a cheater. Firstly, he solved the last three tasks within 10 minutes, secondly, he used a different programming style in each of these three tasks. For example, in G it uses #include <bits/stdc++.h>, and does not use in F. Thirdly, it always uses different variable names to store the number of tests. You can view its codes yourself:

F -> 276290958

G -> 276285830

H -> 276281919