#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;
  vector<int> W,A,C;
  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 b=true;
  rep(i,n){
    if(W[i]>A[m+i]) b=false;
  }
  rep(i,m){
    if(C[i]<A[i]) b=false;
  }
  if(b) cout<<"Yes"<<endl;
  else cout<<"No"<<endl;
  
  return 0;
}