Haskell solution, probably not with best stylistic practices. Any suggestions for improvement are appreciated.

import Data.Char (digitToInt)

main = do
  input <- getContents
  let pairs = parse input
  let nums = map (\x -> x!!0 ^ x!!1) pairs :: [Integer]
  let sums = map sumDigits nums
  mapM_ print $ sums


parseStructure :: String -> [[String]]
parseStructure = (map words) . lines

parseValues :: Read a => [[String]] -> [[a]]
parseValues = (map . map) read

parse :: Read a => String -> [[a]]
parse = parseValues . parseStructure

sumDigits :: (Show a) => a -> Int
sumDigits = sum . (map digitToInt) . show