#include <bits/stdc++.h>
using namespace std;
 
int main() {
  string a;
  cin >> a;
  int r = 1;
for(int i = 0;i < a.size();i++){
  if((i%2==0 && a.at(i)=='L') || (i%2==1 && a.at(i)=='R'))r = 0;
}
  if(r==1)cout << "Yes" << endl;
  else cout << "No" << endl;
}