Why dimokaragiannis ?

My name is Dimosthenis Karagiannis but since I remember myself everybody calls me Dimos. So it would be more logical to use dimoskaragiannis than dimokaragiannis – the difference is just an (s). The reason that I ‘ve picked the latter is because of twitter’s limit on max length for its usernames. I have a pretty big name and surname and even if I used my short name (Dimos) and surname I would still exceed twitter’s limit. I would have picked dimka(nickname that I got on my first year in university which was given to me by the Computer’s Lab of Physics School,Aristotle University of Thessaloniki automatic system) but this was very common and already taken in both twitter.com and wordpress.com