object Main extends App {
  import scala.io.StdIn._
  val odd = "RUD"
  val even = "LUD"
  val str = readLine.trim
  println(if (str.indices.by(2).forall(i ⇒ odd.contains(str(i))) && str.indices.tail.by(2).forall(i ⇒ even.contains(str(i)))) "Yes" else "No")
}
