#ifdef LOCAL
#include <local.hpp>
#else
#pragma GCC optimize("O3,unroll-loops")
#pragma GCC target("avx2")
#include <bits/stdc++.h>
#define debug(...) (static_cast<void>(0))
#define postprocess() (static_cast<void>(0))
#endif

// #include "atcoder/dsu.hpp"
// #include "atcoder/modint.hpp"
// using mint = atcoder::modint998244353;
// using mint = atcoder::modint1000000007;

using namespace std;
using ll = long long;
using ld = long double;

void solve([[maybe_unused]] int test) {
    ll N, M;
    cin >> N >> M;

    string S;
    cin >> S;

    int ac = 0;
    for (int i = 0; i < (int)S.size(); i++) {
        if (S[i] == 'A') {
            ac++;
        }
        if (S[i] == 'C') {
            if (ac <= 0) {
                cout << "No" << endl;
                return;
            }
            ac--;
        }
    }

    vector<char> S2;
    int cnt_a = 0;
    for (int i = 0; i < (int)S.size(); i++) {
        switch (S[i]) {
            case 'A':
                if (cnt_a < M) {
                    cnt_a++;
                    continue;
                }
                S2.push_back('A');
                break;

            case 'C':
                break;

            case 'W':
                S2.push_back('W');
                break;
        }
    }

    reverse(S2.begin(), S2.end());

    int aw = 0;
    for (int i = 0; i < (int)S2.size(); i++) {
        if (S2[i] == 'A') {
            aw++;
        }
        if (S2[i] == 'W') {
            if (aw <= 0) {
                cout << "No" << endl;
                return;
            }
            aw--;
        }
    }

    cout << "Yes" << endl;
}

int main() {
    ios::sync_with_stdio(false), cin.tie(nullptr);

    int t = 1;
    // cin >> t;
    for (int _t = 1; _t <= t; _t++) solve(_t);

    postprocess();
}