function Main(input) {
var nagasa = input.length;
var loop = 0;
var flag = "Yes";
while(loop != nagasa){
if(loop%2 == 0){
  if(input[loop] == "L"){
    flag = "No";
  }
  //奇数の処理
}else{
  if(input[loop] == "R"){
    flag = "No";
  } 
  //偶数の処理
}
  loop ++;
}
console.log(flag);

}
Main(require("fs").readFileSync("/dev/stdin", "utf8"));