import Control.Applicative ((<$>))
import Data.List (sortBy)
import Data.Function (on)

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

solve :: String -> Int
solve = length . head . filter isPal . tail . sortBy (flip compare `on` length) . segments

isPal :: Eq a => [a] -> Bool
isPal = reverse >>= (==)

segments :: [a] -> [[a]]
segments = concat . scanr (\x y -> [x] : map (x:) y) []