{- This is a simple merge sort -}
 
 module Merge where
                 
 merge :: [Int] -> [Int] -> [Int]
 merge [] x = x  
 merge x [] = x
 merge l1@(a:b) l2@(c:d) | a < c     = a:(merge b l2)
 			| otherwise = c:(merge l1 d)
 
 half [] = []
 half [x] = [x]
 half (x:y:z) = x:r where r = half z
 
 sort [] = []
 sort [x] = [x]
 sort l = merge (sort odds) (sort evens) where
 	     odds = half l
 	     evens = half (tail l)
 
 main =
   appendChan stdout "Enter a list of integers separated by \",\"\n" abort $
   readChan stdin abort $ \ input ->
   appendChan stdout 
       (show (sort (read ("[" ++ (head (lines input)) ++ "]"))))
       abort done