open System
open System.Collections.Generic;

let S =stdin.ReadLine()
[<EntryPoint>]
let sf argv =
    let L = String.length S|>int
    let mutable ok = true
    for i in [0..L-1] do
        match i%2=0 with
        | true -> ok <- if S.[i]= 'L' then false else ok
        | _ -> ok <- if S.[i] = 'R' then false else ok 
    match ok with
    | true -> printfn "Yes"
    |_ -> printfn "No"
    0 
