import Control.Applicative ((<$>))
import Data.List

main :: IO ()
main = do
  solve <$> read <$> getLine >>= print

solve :: Int -> Int
solve = foldr g 0 . unfoldr f
  where
    f x
      | x == 0 = Nothing
      | otherwise = Just (let (q, r) = divMod x 7 in (r, q))
    g x y = x + 10 * y