I'd like to report osylai, he managed to find my password since it was weak and used my solution of problem A and the solution of problem B of Stetsyk who was in my room (after he locked the problem on my account).

These are my solution of problem A and his.

These are Stetsyk's solution of problem B and his.

How did I find him ? he was stupid enough to add his account as a friend from my account.