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

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