Unfortunately the facebookpost of another friend gave the right answer away, and I'd find it unethical to reward someone with the advantage of having insight in my facebook account. It's unfair to those people who actually borrowed books about the Bulgarian history and humour in the library, and I know some of you did!
But since you all (my two main readers) got so excited I will start another competition soon.
For now I say bye with the word "TENG" and a diagonal stroke with my index finger.
PS: that's what koreans say and do to express "you guessed wrong!!"