#include<bits/stdc++.h>
using namespace std;

int main(){
    int n, m; cin >> n >> m;
    string s; cin >> s;
    string wa = "", ac = "";
    for (char c : s){
        if (c == 'W') wa += '(';
        if (c == 'C') ac += ')';
        if (c == 'A'){
            if (m == 0) wa += ')';
            else ac += '(', m--;
        }
    }
    auto check = [&](string t){
        int rui = 0;
        for (char c : t){
            rui += (c == '(' ? 1 : -1);
            if (rui < 0) return false;
        }
        return rui == 0;
    };
    cout << ((check(wa) && check(ac)) ? "Yes" : "No") << endl;
}