import Data.Char (digitToInt)
import Data.List (nub)

factors :: Integral a => a -> [a]
factors n = [f | f <- [1 .. n], mod n f == 0]

numToDigits :: (Integral a, Show a) => a -> [Int]
numToDigits = fmap digitToInt . show

gcdOfPermutation :: Integer -> Integer
gcdOfPermutation n
    | length (nub ds) == 1 = n
    | otherwise = maximum $ filter (\f -> mod n f == 0) (factors $
        fromIntegral $ foldr1 gcd xs)
    where
        ds = numToDigits n
        xs = [9 * abs (ds !! i - ds !! j) | let m = length ds,
            i <- [0 .. m - 1], j <- [0 .. i - 1]]

main :: IO ()
main = do
    n <- readLn :: IO Integer
    print $ gcdOfPermutation n