Hi Codeforces,

I hope you enjoyed the contest despite the difficulty. Do not hesitate to ask questions and discuss the problems here. :)

If you participated, I would really appreciate if you could fill in this short form. It only takes 1 minute and will be useful for my thesis. https://goo.gl/forms/XPfkoRxRjEKmTDt32

Editorial: https://vlecomte.github.io/set/geo18/editorial.pdf

Example solutions:

• A: http://codeforces.net/gym/101793/submission/37926736
• B: http://codeforces.net/gym/101793/submission/37926896
• C: http://codeforces.net/gym/101793/submission/37926999
• D: http://codeforces.net/gym/101793/submission/37927106

Thanks to all who participated! :)