#include <bits/stdc++.h>
using namespace std;
signed main() {
  string s;
  cin >> s;
  long long flg = 1;
  for (long long i = 0; i < s.size(); i++) {
    if (i % 2 == 0 && s[i] == 'L') flg = 0;
    if (i % 2 == 1 && s[i] == 'R') flg = 0;
  }
  if (flg)
    cout << "Yes" << endl;
  else
    cout << "No" << endl;
  return 0;
}
