-- 11 - biggest multiple in 2d field
parseSquare :: String -> [[Integer]]
parseSquare = map (\line -> map read $ words line) . lines

columns :: [[a]] -> [[a]]
columns [[]] = []
columns xs = map 

main :: IO ()
main = do
  fileString <- readFile "problem_11.txt"
  putStrLn . show $ parseSquare fileString