#include <bits/stdc++.h>
using namespace std;
int main() {
  ios::sync_with_stdio(0);
  cin.tie(0);
  string s;
  cin >> s;
  if (count(s.begin(), s.end(), 'R') * 2 > s.size())
    cout << "Yes";
  else
    cout << "No";
}
