check :: String -> Bool
check s = checkEven s
checkEven [] = True
checkEven (c:s) = (c == 'R' || c == 'U' || c == 'D') && checkOdd s
checkOdd [] = True
checkOdd (c:s) = (c == 'L' || c == 'U' || c == 'D') && checkEven s

main = do
  s <- getLine :: IO String
  putStrLn $ if check s then "Yes" else "No"
