#include <bits/stdc++.h>
using namespace std;
int main() {
  string s;
  int cnt = 0;
  cin >> s;
  for (int i = 0; i < s.size(); i++) {
    if (s[i] == 'R') cnt++;
  }
  bool ans = (s.size() - cnt < cnt);
  puts(ans ? "Yes" : "No");
  return 0;
}
