What information security conferences are worth attending?

Question

Information Security

Good afternoon. The Internet is full of information about conferences zero nights, defcon and so on.
I have never been to such events, I want to go.
Advise which are the most interesting and informative, where it is definitely worth going? Preferably St. Petersburg, Moscow time.
Conferences outside the Russian Federation are also interested
. Thank you.

Answer 1

phd
blackhat
next HOPE