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