#include<bits/stdc++.h>
using namespace std;
int main(){
  string s;
  cin >> s;
  int ans = 1;
  for(int i = 0; i < s.length(); i++){
    if(s[i] == 'L')
      ans = 0;
    i++;
    if(s[i] == 'R')
      ans = 0;
  }
  if(ans == 1)
    cout << "Yes";
  else
    cout << "No";
}