import Control.Applicative
import Control.Monad
import Data.List
import Data.Array
import Data.Char

main = do
  s <- getLine
  let ans = fst $ foldl (\(isEasy, isEven) c -> if isEven && c /= 'R' then (isEasy && True, False) else if not isEven && c /= 'L' then (isEasy && True, True) else (False, not isEven)) (True, False) s
  putStrLn $ if ans then "Yes" else "No"
