Hello!
IOI 2018 is just around the corner and so I decided to propose the push-up challenge. The Bulgarian team has been doing it for the past couple of years and in a way it is very fun. If someone isn't familiar woth the rules, he can check the blog post of this challenge from 2015 (link).
So feel free to share your coefficients if you are going to join!
PS: Although I suggest you do the push-up challenge, if you are too lazy for it (and you can legally drink), you can do the drinking challenge instead (the rules are similar but with drinking C ml of 40% alcohol instead).