#include <bits/stdc++.h>
using namespace std;
int main() {
  int n;
  int cnt = 0;
  for (int i = 0; i < n; ++i) {
    char c;
    cin >> c;
    if (c == 'R')
      ++cnt;
    else if (c == 'B')
      --cnt;
  }
  cout << (0 < cnt ? "Yes" : "No");
}
