fun main(args: Array<String>) {
  val s = readLine()!!.split("")
  var d = "Yes"
  for (i in 1 until s.size) {
    if (i % 2 == 0 && s[i].equals("R")) {
      d = "No"
      break
    } else if (i % 2 == 1 && s[i].equals("L")) {
      d = "No"
      break
    }
  }  
  println(d)
}