object Main {
  def main(args:Array[String]) = {
    val sc = new java.util.Scanner(System.in)
    var result = "Yes"
    val s = sc.next
    for(i <- 0 to s.length-1) {
      (i%2, s(i)) match {
        case (1, 'R') => result="No"
        case (0, 'L') => result="No"
        case _        => ()
      }
    }
    println(result)
  }
}
