import Control.Monad

main = getLine >>= print . maximum1 . cww

cww :: String -> [Int]
cww n = do
  let l = length n
  i <- [0 .. l-1]
  j <- [i+1 .. l-1]
  k <- [j+1 .. l-1]
  let (c,w1,w2) = (n!!i, n!!j, n!!k)
  guard ((c /= '0') && (c /= w1) && (w1 == w2))
  let next = map snd $ filter (flip notElem [i,j,k] . fst) $ zip [0..] n
  let x = read [c,w1,w2]
  return (x + maximum1 (cww next))

maximum1 xs = if null xs then 0 else maximum xs