object Main extends App {	
  val in = readLine.split("").tail
  val oddStr = List("R", "U", "D")
  val evenStr = List("L", "U", "D")
  val odd = (1 to in.length - 1 by 2).map(i => in(i)).forall(s => oddStr.contains(s))
  val even = (0 to in.length - 1 by 2).map(i => in(i)).forall(s => evenStr.contains(s))
  println(if(even && odd) "Yes" else "NO")
}