fun main(args: Array<String>){
	val S = readLine()!!
  	var flag = true
  	for(i in 0 until S.length){
    	if((i%2==0 && S[i] == 'L') || (i%2==1 && S[i] == 'R')){
        	flag = false
         	break
        }
    }
  print(if(flag) "Yes" else "No")
	
}