#include <bits/stdc++.h>
using namespace std;
int main() {
    ios::sync_with_stdio(false);
    cin.tie(nullptr);
    int N, M;
    if (!(cin >> N >> M)) return 0;
    string s; cin >> s;
    int L = (int)s.size();
    vector<int> prefW(L+1,0), suffC(L+1,0);
    for (int i = 0; i < L; ++i) prefW[i+1] = prefW[i] + (s[i]=='W');
    for (int i = L-1; i >= 0; --i) suffC[i] = suffC[i+1] + (s[i]=='C');

    int Xw = 0, Xc = 0;
    for (int i = 0; i < L; ++i) {
        if (s[i] != 'A') continue;
        bool hasWBefore = (prefW[i] > 0);    // any W at index < i
        bool hasCAfter  = (suffC[i+1] > 0); // any C at index > i
        if (!hasWBefore && !hasCAfter) {
            cout << "No\n";
            return 0;
        }
        if (hasWBefore) ++Xw;
        if (hasCAfter) ++Xc;
    }

    if (Xw >= N && Xc >= M) cout << "Yes\n";
    else cout << "No\n";
    return 0;
}