#include <bits/stdc++.h>
#include <atcoder/all>
#define OVERLOAD_REP(_1, _2, _3, name, ...) name
#define REP1(i,n) for (auto i = std::decay_t<decltype(n)>{}; (i) < (n); ++(i))
#define REP2(i,l,r) for (auto i = (l); (i) != (r); ++(i))
#define rep(...) OVERLOAD_REP(__VA_ARGS__, REP2, REP1)(__VA_ARGS__)
#define all(a) (a).begin(),(a).end()
#define rall(a) (a).rbegin(),(a).rend()
using namespace std;
using namespace atcoder;
using ll = long long;
using ull = unsigned long long;
using P = pair<int,int>;
using PP = pair<long long,int>;
using LP = pair<long long,long long>;
using mint1 = modint1000000007;
using mint9 = modint998244353;
const int INF = 1'000'000'100;
const long long LINF = 1'000'000'000'000'100'000;
const int di[] = {0,1,0,-1,-1,1,-1,1};
const int dj[] = {1,0,-1,0,1,1,-1,-1};
template<class T> inline bool chmin(T& a, T b){if(a>b){a=b;return true;}return false;}
template<class T> inline bool chmax(T& a, T b){if(a<b){a=b;return true;}return false;}
void YesNo (bool ok,const string& s="Yes",const string& t="No") {if(ok)cout<<s<<endl;else cout<<t<<endl;}


//-----def end-----//

bool f (string s) {
    int l = 0 , r = 0;
    for(char c : s) {
        if(c == '(') l++;
        else r++;
        if(l < r) return false;
    }
    return (l == r);
}

int main () {
    int n , m;
    string s;
    cin >> n >> m >> 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--;
        }
    }
    YesNo(f(ac)&&f(wa));
    return 0;
}