Reyna's submission of Problem A in today's contest got Wrong Answer verdict.As Reyna is very good at coding,I felt a little strange.However,when I looked at the detailed feedback,it showed that it couldn't find a file,which I never saw before.More strangely,I re-submitted Reyna's code and then got AC verdict.
So,could anyone tell me what the reason was or it was a bug in Codeforces? Thanks!
UPD: The issue is fixed now.