fun main(args: Array<String>) {
    val S = readLine()!!
    println(if (isEasy(S)) "Yes" else "No")
}

private fun isEasy(S: String) : Boolean {
    for (i in 0 until S.length) {
        if ((i+1).and(1) == 0) {
            if (S[i] == 'R') {
                return false
            }
        } else {
            if (S[i] == 'L') {
                return false
            }
        }
    }
    return true
}
