[Reyna's submission](http://mirror.codeforces.com/contest/814/submission/27632209) of [Problem A in today's contest](http://mirror.codeforces.com/problemset/problem/814/A) got Wrong Answer verdict.As [user:Reyna,2017-06-07] 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 [user:Reyna,2017-06-07]'s code and then got AC verdict.↵
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[Submission](http://mirror.codeforces.com/contest/814/submission/27652681) ↵
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So,could anyone tell me what the reason was or it was a bug in Codeforces? Thanks!
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[Submission](http://mirror.codeforces.com/contest/814/submission/27652681) ↵
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So,could anyone tell me what the reason was or it was a bug in Codeforces? Thanks!