I don't know these people but I had graduated from one of these departments and get my information from classmates and my own experience (I got 4-5, the reason

I don't know these people but I had graduated from one of these departments and get my information from classmates and my own experience (I got 4-5, the reason I could solve such a problem is that I grinded a lot). PS. These people you mentioned are from the St. Petersburg uni, where I have never been, it could be different there. I can only speak for the Moscow.