getting compliation error in EIUASSEMBLY spoj

I’m getting an error of kind “prog.cpp:41: error: integer constant is too large for ‘long’ type”
I’m not able to get rid of this error

please help me out.
code link:- link text

Question link?

Well, your code was having some kind of overflow that’s why you’re getting the error. Just a little modification in finding mid and woah your code got submitted. Here is the link Ideone . Tip: Always use this method of finding mid to deal with overflow.
Mid = Low + (High - Low)/2

Can a some one give a detailed solution to this problem.