let () =
  let s = read_line () in
  print_endline @@
  if
    Array.fold_left ( && ) true @@
    Array.init (String.length s) @@ fun i ->
      match s.[i], i mod 2 with
      | ('R' | 'U' | 'D'), 0
      | ('L' | 'U' | 'D'), 1 -> true
      | _ -> false 
  then "Yes"
  else "No"
