#include <iostream>
#include <cstdlib>
#include <string>
using namespace std;

int main(){
  string s;
  int N;
  cin >> s;
  cin >> N;
  int rc,bc;
  for(int i = 0; i < N; i++){
  
    if(s[i] == 'R')
      rc++;
    else 
      bc++,
}
  if(rc > bc)
    cout << "Yes" <<endl;
  else
    cout << "No" << endl;
}
