import Data.Char
import Data.List
import Numeric

fromStringToBit :: String -> Int
fromStringToBit s = fst $ head $ readInt 2 (`elem` "01") digitToInt t
    where
        t = map (\x -> if x == 'L' then '0' else '1') s

tree :: Int -> [[Int]]
tree = unfoldr f
    where
        f 0 = Nothing
        f 1 = Just ([1], 0)
        f x = Just ([2 ^ (x - 1) .. (2 ^ x - 1)], x - 1)

main :: IO ()
main = do
    s <- getLine
    let t = fromStringToBit s
        u = tree $ (length s) + 1
    print $ (head u) !! t