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