import Data.Set (Set)
import qualified Data.Set as S

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

isMow :: String -> Bool
isMow cs = ((S.size $ S.fromList cs) == 1) && (head cs == '3')

solve :: String -> Int
solve s | head s /= '1'        = -1
        | not $ isMow $ tail s = -1
        | otherwise            = length $ tail s