https://mirror.codeforces.com/contest/1296/submission/330147535
this is my solution using dictionary in python3.
maybe, there could be a lot of positions in 2D with collisions.
https://mirror.codeforces.com/contest/1296/submission/330147535
this is my solution using dictionary in python3.
maybe, there could be a lot of positions in 2D with collisions.