#include <bits/stdc++.h>
using namespace std;
int main() {
  string s;
  cin >> s;
  string y = "Yes";
  string n = "No";
  int ct = 0;
  for (auto ch : s) {
    if (ch == 'R') ct++;
  }
  string ret = n;
  if (ct > s.size() - ct) ret = y;
  cout << ret << endl;
}
