--
-- Find the greatest product of five consecutive digits in the 1000-digit number.
--

number
    = "73167176531330624919225119674426574742355349194934"
   ++ "96983520312774506326239578318016984801869478851843"
   ++ "85861560789112949495459501737958331952853208805511"
   ++ "12540698747158523863050715693290963295227443043557"
   ++ "66896648950445244523161731856403098711121722383113"
   ++ "62229893423380308135336276614282806444486645238749"
   ++ "30358907296290491560440772390713810515859307960866"
   ++ "70172427121883998797908792274921901699720888093776"
   ++ "65727333001053367881220235421809751254540594752243"
   ++ "52584907711670556013604839586446706324415722155397"
   ++ "53697817977846174064955149290862569321978468622482"
   ++ "83972241375657056057490261407972968652414535100474"
   ++ "82166370484403199890008895243450658541227588666881"
   ++ "16427171479924442928230863465674813919123162824586"
   ++ "17866458359124566529476545682848912883142607690042"
   ++ "24219022671055626321111109370544217506941658960408"
   ++ "07198403850962455444362981230987879927244284909188"
   ++ "84580156166097919133875499200524063689912560717606"
   ++ "05886116467109405077541002256983155200055935729725"
   ++ "71636269561882670428252483600823257530420752963450"

chunkSize = 5

chunks
    = map (\ x -> take chunkSize $ drop x number) [0 .. length number - chunkSize]

toNumbers :: String -> [Int]
toNumbers
    = map (\ x -> read [x] :: Int)


main = print $ maximum $ map (product . toNumbers) chunks

