fun calc141B(s:String): String{
    val a = s.filterIndexed{i, c -> i % 2 == 0}.all { "RUD".contains(it) } &&
            s.filterIndexed{i, c -> i % 2 == 1}.all { "LUD".contains(it) }
    return if (a) "Yes" else "No"
}


fun main(args:Array<String>) {
    val S = readLine()!!
    println(calc141B(S))
}
