#include <bits/stdc++.h>
using namespace std;
string s;
int a, b;
int main() {
  cin >> s;
  for (char c : s) {
    if (c == 'R')
      a++;
    else
      b++;
  }
  printf("%s\n", a > b ? "Yes" : "No");
  return 0;
}
