#include <bits/stdc++.h>
using namespace std;
int32_t main() {
  ios::sync_with_stdio(false);
  cin.tie(NULL);
  cout.precision(10);
  int r = 0, b = 0;
  string s;
  cin >> s;
  int n;
  cin >> n;
  for (int i = 0; i < n; ++i) {
    if (s[i] == 'R')
      r++;
    else
      b++;
  }
  cout << (r > b ? "Yes" : "No");
}
