#define rep(i,n) for(int i=0;i<(int)(n);i++)
#define ALL(v) v.begin(),v.end()
typedef long long ll;
 
#include<bits/stdc++.h>
using namespace std;
 
int main(){
  ios::sync_with_stdio(false);
  std::cin.tie(nullptr);

  int n,m;
  string s;
  cin>>n>>m>>s;
  priority_queue<int> qa,qc;
  priority_queue<int, vector<int>, greater<int> > qw;
  rep(i,n+m){
    if(s[i]=='W') qw.push(i);
    else if(s[i]=='A') qa.push(i);
    else qc.push(i);
  }
  while(qw.size()){
    if(qa.top()<qw.top()){
      cout<<"No"<<endl;
      return 0;
    }
    qa.pop();
    qw.pop();
  }
  while(qc.size()){
    if(qa.top()>qc.top()){
      cout<<"No"<<endl;
      return 0;
    }
    qa.pop();
    qc.pop();
  }
  cout<<"Yes"<<endl;
  
  return 0;
}