This is pdfTeX, Version 3.14159265-2.6-1.40.19 (TeX Live 2018) (preloaded format=pdflatex 2018.4.16)  26 OCT 2018 16:56
entering extended mode
 restricted \write18 enabled.
 file:line:error style messages enabled.
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**problem.en.tex
(./problem.en.tex
LaTeX2e <2018-04-01> patch level 2
Babel <3.18> and hyphenation patterns for 84 language(s) loaded.
./problem.en.tex:1: Undefined control sequence.
l.1 \problemname
                {Maximum Subarrays}
? 
./problem.en.tex:1: Emergency stop.
l.1 \problemname
                {Maximum Subarrays}
End of file on the terminal!

 
Here is how much of TeX's memory you used:
 5 strings out of 492649
 139 string characters out of 6129622
 56400 words of memory out of 5000000
 3988 multiletter control sequences out of 15000+600000
 3640 words of font info for 14 fonts, out of 8000000 for 9000
 1141 hyphenation exceptions out of 8191
 5i,0n,1p,48b,8s stack positions out of 5000i,500n,10000p,200000b,80000s
./problem.en.tex:1:  ==> Fatal error occurred, no output PDF file produced!