Reference

https://www.acmicpc.net/problem/10999

https://www.acmicpc.net/problem/1395
https://www.acmicpc.net/problem/2357
https://www.acmicpc.net/problem/2042
https://www.acmicpc.net/problem/10868
https://algospot.com/judge/problem/read/MORDOR

