fun main(args: Array<String>) {
    val s = readString()
    var ans = true
    s.forEachIndexed { index, c ->
        when {
            index % 2 == 0 -> if (c == 'L') ans = false
            else -> if (c == 'R') ans = false
        }
    }
    println(if (ans) "Yes" else "No")
}

// Tools
fun readString() = readLine()!!