#include <bits/stdc++.h>
using namespace std;

int main(){
  string S;
  cin>>S;
  for(int i=0; i<S.size(); i++)
    if((i%2 == 0 && S[i]=='L') || (i%2 == 1 && S[i]=='R')){
      cout<<"No"<<endl;
      return 0;
    }
  cout<<"Yes"<<endl;
}
