[Haskell-beginners] Hint on exercise from Real World Haskell

[Chris Saunders]

I have been working on the exercises from chapter 1 of Real World Haskell. 
I seem to be stuck on a solution to:

4.Modify the WC.hs example again, to print the number of characters in a 
file.

I'm hoping to get a hint for this one.  I may request a solution later but 
for now I would prefer just a hint.

Regards
Chris Saunders