fun main(args:Array<String>){
    val s = readLine()!!
    var ok = true
    for(i in 0 until s.length step 2){
        if(s[i] == 'L') ok = false
    }
    for(i in 1 until s.length step 2){
        if(s[i] == 'R') ok = false
    }
    println(if(ok) "Yes" else "No")
}
