#include <bits/stdc++.h>
using namespace std;
int main() {
  string s;
  cin >> s;
  int n = 0;
  for (int i = 0; i < s.length(); i++) {
    if (s[i] == 'R') n++;
  }
  cout << (s.length() < n * 2 ? "Yes" : "No") << endl;
}
