By the way, thank you for making your posts that are required for battling 101 something more than "me too" posts. It is appreciated.

Yes, the signature length rules are going to make it a real pain. You could do multiple statements on a single line, but I will take away points for that. (Points are imaginary).

Perhaps:

if(int.TryParse(Console.Readline(), out i) && i > 9000)

But make sure to assign i a value, or this won't compile.

The code in your signature will throw an invalid cast exception. Please fix.

Actually, it won't even compile.