Today I tried to solve the problem with MO, using Hilbert curve (https://codeforces.com/gym/102069/problem/D). I was surprised to see that I am gaining 38 points (that means, that the group with n <= 5000 and the group, where there is no update of the element’s requests, passes (that means the Hilbert curve is written correctly)). Is it possible to optimize MO with an element update using Hilbert curve?