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