-- sort ns returns a sorted version of the list ns.
-- For example:
--   sort [1,2,3,4] = [1,2,3,4]
--   sort [4,3,2,1] = [1,2,3,4]
--   sort [3,1,4,2] = [1,2,3,4]
--   sort [3,2,3,1] = [1,2,3,3]
-- Hint: I suggest that you try to implement an
-- ***insert***ion sort :-)

sort       :: [Int] -> [Int]
sort []     = []
sort       :: [Int] -> [Int]
sort []     = []
sort []     = []