#include<bits/stdc++.h>
// #include<atcoder/all>
// #include<boost/multiprecision/cpp_int.hpp>

using namespace std;
// using namespace atcoder;
// using bint = boost::multiprecision::cpp_int;
using ll = long long;
using ull = unsigned long long;
using P = pair<int,int>;
#define rep(i,n) for(ll i = 0;i < (ll)n;i++)
#define ALL(x) (x).begin(),(x).end()
// #define MOD 1000000007
#define MOD 998244353


int main(){
  
  int n,m;
  string s;
  cin >> n >> m >> s;
  deque<int> w,c,a;
  rep(i,2*(n+m)){
    if(s[i] == 'W')w.push_back(i);
    else if(s[i] == 'A')a.push_back(i);
    else c.push_back(i);
  }
  bool is = true;
  while(!w.empty()){
    if(a.empty()){
      is = false;
      break;
    }
    if(w.back() > a.back())is = false;
    w.pop_back();a.pop_back();
  }
  while(!c.empty()){
    if(a.empty()){
      is = false;
      break;
    }
    if(c.front() < a.front())is = false;
    c.pop_front();a.pop_front();
  }
  cout << (is ? "Yes\n" : "No\n");
  

  return 0;
}