let s = stdin.ReadLine() 
let n = s.Length

let f x =if (x%2=0 && s.[x-1]<>'R') || (x%2=1 && s.[x-1]<>'L') then 0 else 1


[1..n]
|>List.sumBy f
|>fun x -> if x>0 then "No" else "Yes" 
|>stdout.WriteLine