Hi Codeforces!
I want to tell you about the annual programming contest, hosted by Spain-based company Tuenti.
This year the online phase will take place from 27 April to 4 May. I participated last year, and the format of the online phase was quite interesting. Besides the usual algorithmic problems, there were problems on cryptography, like MitM attack of Diffie-Hellman or AES bruteforce, and problems "without description", when one should guess it from hidden hints. Problems had to be solved consecutively, so that a participant could not read the next one unless she solved the previous. But several passes were allowed.
Details:
duration: 7 days
prizes include cloth and gadgets :-)