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