function Main(input) {
  input = input.split("\n");
  s = input[0].split("");
  var ans ="Yes";
  for(var i=0;i<s.length;i++){
    if(i%2==0){
      if(s[i]=="L"){
        ans = "No";
      }
    }else if(i%2==1){
      if(s[i]=="R"){
        ans = "No";
      }
    }
  }
  console.log(ans);
}
Main(require("fs").readFileSync("/dev/stdin", "utf8"));