#include <bits/stdc++.h>
#include <atcoder/all>
 
#define elif else if
#define ll long long
#define vll vector<long long>
#define vec vector
#define embk emplace_back
#define rep(i, n) for (int i = 0; i < n; i++)
#define rep3(i, n, k) for (int i = k; i < n; i++)
#define all(a) a.begin(), a.end()
 
using namespace std;
using namespace atcoder;
const ll INF = 1LL << 60;
const ll mod = 998244353;

int main() {
  ll n, m; cin >> n >> m;
  string s; cin >> s;
  ll ss = s.size();
  
  vec<bool> used(ss);
  deque<ll> posa;
  ll count = 0;
  rep(i, ss) {
    if (s[ss-i-1] == 'A') {
      count++;
      posa.push_back(ss-i-1);
    }
    elif (s[ss-i-1] == 'W') {
      count--;
      used[posa.front()] = 1;
      posa.pop_front();
      
      if (count < 0) {
        cout << "No" << endl;
        return 0;
      }
    }
  }
    
  rep(i, ss) {
    if (s[i] == 'C') {
      if (posa.back() < i) {
        used[posa.back()];
        posa.pop_back();
      }
      else {
        cout << "No" << endl;
        return 0;
      }
    }
  }
  
  cout << "Yes" << endl;
  
}