fun main(args : Array<String>) {
    val S = readLine()!!
    
    
    val rud = setOf('R', 'U', 'D')
    val lud = setOf('L', 'U', 'D')

    S.forEachIndexed { index, c ->
        val set = if (index % 2 == 0)  rud else lud
        if (!set.contains(c)) {
            println("No")
            return
        }
    }
    println("Yes")
}