#include <bits/stdc++.h> using namespace std; using ll = long long; int main() { cin.tie(nullptr); ios::sync_with_stdio(false); int N,M; cin>>N>>M; string S,T,U; cin>>S; for(auto s:S){ if(s=='W')T.push_back(s); else if(s=='A'&&M==0)T.push_back(s); else if(s=='A'){ U.push_back(s); M--; } else U.push_back(s); } int k=0; for(auto t:T){ if(t=='W')k++; else if(k==0){ cout<<"No"<<endl; return 0; } else k--; } for(auto t:U){ if(t=='A')k++; else if(k==0){ cout<<"No"<<endl; return 0; } else k--; } cout<<"Yes"<<endl; }