#include<iostream>
#include<string>
using namespace std;
int main(){
  int i;string s;bool ng = false;cin >> s;
  for (i=0;i<s.size();i++){
    if ((i%2==0 && s[i]=='L')||(i%2==1 && s[i]=='R')) ng = true;
  }
  cout << ((ng) ? "No":"Yes") << endl;
}