#include <bits/stdc++.h>
using namespace std;
const int MOD = 1e9 + 7;
const int INF = 1e9;
int main() {
  long long n;
  string s;
  cin >> s;
  long long l = 0, r = 0;
  for (__typeof(n) i = 0; i < n; i++) {
    if (s[i] == 'R')
      r++;
    else
      l++;
  }
  if (r > l)
    cout << "YES"
         << "\n";
  else
    cout << "NO"
         << "\n";
}
