import Control.Applicative
import Data.List
import Data.Bits (popCount)

solve n = (\x -> if last x == [] then -1 else 1+length x) $ unfoldr next (1,[[1]]) where
  next :: (Int,[[Int]]) -> Maybe ([Int],(Int,[[Int]]))
  next (m,h'@(h:hs))
    | n `elem` h || h == [] = Nothing
    | otherwise = let k = nub $ h >>= flip step h' in Just (k,(m+1,k:h'))

  step :: Int -> [[Int]] -> [Int]
  step j hs = [i|i<-fmap ((j+) . (*popCount j)) [1,-1], 1<=i, i<=n, all (notElem i) hs]

main = do
  n <- (read :: String -> Int) <$> getLine
  print $ solve n