#include <bits/stdc++.h>
using namespace std;
int main() {
  string s;
  int c = 0;
  cin >> s;
  for (int i = 0; i < s.size(); i++) {
    if (s[i] == 'R') c++;
  }
  if (s.size() - c < c)
    cout << "Yes" << endl;
  else
    cout << "No" << endl;
}
