Sick Travellers - problem was added

Just it. Welcome to try / test it, report any issues. Probably we could put here the full name of our colleague kbobrov92 who proposed it - if I can know it :)

Sick Travellers

I believe problem would not be hard (I've tagged it "implementation"), though hopefully we'll be able to add some advanced version later.

Also it is really interesting to play with parameters and see how disease spreads or dies out :)

Thanks - I've updated the link in the problem statement :)