#include <bits/stdc++.h>
using namespace std;
int main(){
string S; cin >> S;
int N=S.size();
for(int i=0; i<N; i++){
if(i%2){ if(S[i]=='R'){ cout << "No" << "\n"; return 0; } }
else{ if(S[i]=='L'){ cout << "No" << "\n"; return 0; } }
}
cout << "Yes" << "\n";
}