#include <bits/stdc++.h>
using namespace std;

/*main*/
int main() {
  int n,m; cin >> n >> m;
  string s; cin >> s;
  int count=0;
  for(int i=0;i<s.length();i++){
    if(s.at(i)=='W') count++;
    else if(s.at(i)=='A' && count>0) count--;
  }
  if(count){
    cout << "No" << endl;
    return 0;
  }
  for(int i=s.length()-1;i>=0;i--){
    if(s.at(i)=='C') count++;
    else if(s.at(i)=='A' && count>0) count--;
  }
  if(count){
    cout << "No" << endl;
    return 0;
  }

  cout << "Yes" << endl;

  return 0;
}