#include <iostream>
using namespace std;

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