See where the closing quotes are, that's a new line.

Hello,
I am writing in c# code. It all passed except "1234
" I can't tell if that is a space at the end of 4 in one of the tests?

My apologies I mark spoiler moving forward. I will work with this. Thank you.

Please mark your post as having spoiler content next time.

using system; is not the same as using System;

You have a typo there, and that's what hobovsky told you before.

You'd need to give some more details (your code or the exact error message), because namespace System is definitely present and should be available (although system is not).

Hello,
I tested my code on my end and it works. I got an code.cs(1,7)error cs0246: The type of namespace name 'system' could not be found. Are you missing an assembly reference? I look up error and it says to update nuget packages? Please advise.

I am not sure what happened. I uploaded my code and it said unexpected answers, however my outputs were the exact same answers it was expecting. Is there something else that I should be doing? My code works fine in my editor. I am using JavaScript.