let () =
    let main () =
        let s       = read_line () in
        let l = String.length s in
        let rec loop i =
            if i = l then true else
                match i mod 2, s.[i] with
                | 0, 'L' -> false
                | 1, 'R' -> false
                | _ -> loop (i + 1)
        in
        print_endline (if loop 0 then "Yes" else "No")
    in
    main ()