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