fun main(args: Array<String>) {
    val S = readLine()!!
    var ans = true
    S.forEachIndexed { index, char ->
        if (index % 2 == 0) {
            if (char != 'R' && char != 'U' && char != 'D') { ans = false }
        } else {
            if (char != 'L' && char != 'U' && char != 'D') { ans = false }
        }
    }
    println(if (ans) "Yes" else "No")
}