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import Data.Foldable (toList)
import Data.Sequence hiding (zip)
import Prelude hiding (replicate)
type FS = Seq (Maybe Int)
showFS :: FS -> String
showFS = Prelude.reverse . go []
where
go :: String -> FS -> String
go res Empty = res
go res (x :<| xs) = go (f x : res) xs
f :: Maybe Int -> Char
f Nothing = '.'
f (Just x) = head $ show x
rearrange :: FS -> FS -> FS
rearrange result Empty = result
rearrange result (x@(Just _) :<| rest) =
rearrange (result :|> x) rest
rearrange result (Nothing :<| (rest :|> x@(Just _))) =
rearrange (result :|> x) rest
rearrange result (rest@(Nothing :<| _) :|> Nothing) =
rearrange result rest
parse :: String -> FS
parse = go 0 Empty
where
go :: Int -> FS -> String -> FS
go _ res [] = res
go n res (x:xs) = go' (n+1) (res <> f x (Just n)) xs
go' :: Int -> FS -> String -> FS
go' _ res [] = res
go' n res (x:xs) = go n (res <> f x Nothing) xs
f :: Char -> Maybe Int -> FS
f x y = let n = read . pure $ x
in replicate n y
catMaybes :: Seq (Maybe a) -> Seq a
catMaybes Empty = Empty
catMaybes (Nothing :<| xs) = catMaybes xs
catMaybes (Just x :<| xs) = x :<| catMaybes xs
checksum :: FS -> Int
checksum = sum . fmap (uncurry (*)) . zip [0..] . toList . catMaybes
main :: IO ()
main = getLine >>= print . checksum . rearrange Empty . parse
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