bugs?
I would like to give some feedback about ...
From: https://www.checkio.org/mission/shortest-knight-path/solve/
HTTP_USER_AGENT:
Mozilla/5.0 (Windows NT 6.1; WOW64; rv:44.0) Gecko/20100101 Firefox/44.0
my code seem run time error? but it's worked on my computer by use your test data