import           Control.Exception (assert)
import           Data.Bits         (bit)
import           Data.Char         (digitToInt)
import           Data.List         (group, maximumBy, minimumBy, sort,
                                    transpose)
import           Data.Ord          (comparing)

main :: IO ()
main = do
  diagnostics <- getContents
  putStrLn (solution1 diagnostics)

solution1 :: String -> String
solution1 diagnostics = show (calcGamma * calcEpsilon)
  where
    calcGamma = listToBit (map most (parseDiagnostics diagnostics))
    calcEpsilon = listToBit (map least (parseDiagnostics diagnostics))

parseDiagnostics :: String -> [[Int]]
parseDiagnostics diagnostics = map (map digitToInt) (transpose (lines diagnostics))

most :: [Int] -> Int
most = head . (maximumBy (comparing length)) . group . sort

least :: [Int] -> Int
least = head . (minimumBy (comparing length)) . group . sort

listToBit :: [Int] -> Int
listToBit list = foldr (\b acc -> (acc + toBit b)) 0 (enumerate (reverse list))
  where
    -- Takes a location and value to converts it to the appropriate
    -- integer.
    toBit :: (Int, Int) -> Int
    toBit (i, b) = if b == 1
                   then bit i
                   else 0
    enumerate :: [a] -> [(Int, a)]
    enumerate = zip [0..]

-- Tests

testInput1 :: String
testInput1 = unlines [
  "00100",
  "11110",
  "10110",
  "10111",
  "10101",
  "01111",
  "00111",
  "11100",
  "10000",
  "11001",
  "00010",
  "01010"
  ]

test1 :: String
test1 = assert ((solution1 testInput1) == "198") "success"