-- Problem 8
-- (0.00 secs, 2,602,832 bytes)

import Data.Char (digitToInt)
import Data.List (tails, transpose)

e008 = do
    n <- readFile "../res/e008.txt"
    print . maximum . map product . transpose 
          . take 13 . tails . map digitToInt 
          . concat . lines $ n