#include <bits/stdc++.h>
using namespace std;
int main() {
  string s;
  cin >> s;
  int count1 = 0, count2 = 0;
  for (int i = 0; i < s.size(); i++) {
    if (s[i] == 'R') count1++;
  }
  for (int i = 0; i < s.size(); i++) {
    if (s[i] == 'B') count2++;
  }
  if (count1 > count2)
    cout << "Yes" << endl;
  else
    cout << "No" << endl;
}
