#include <bits/stdc++.h>
#pragma GCC optimize("Ofast")
using namespace std;
using std::cout;
using std::cin;
using std::endl;
using ll=long long;
using ld=long double;
ll ILL=2167167167167167167;
const int INF=2100000000;
const ll mod=998244353;
#define rep(i,a) for (int i=0;i<a;i++)
#define all(p) p.begin(),p.end()
template<class T> using _pq = priority_queue<T, vector<T>, greater<T>>;
template<class T> ll LB(vector<T> &v,T a){return lower_bound(v.begin(),v.end(),a)-v.begin();}
template<class T> ll UB(vector<T> &v,T a){return upper_bound(v.begin(),v.end(),a)-v.begin();}
template<class T> bool chmin(T &a,const T &b){if(a>b){a=b;return 1;}else return 0;}
template<class T> bool chmax(T &a,const T &b){if(a<b){a=b;return 1;}else return 0;}
template<class T> void So(vector<T> &v) {sort(v.begin(),v.end());}
template<class T> void Sore(vector<T> &v) {sort(v.begin(),v.end(),[](T x,T y){return x>y;});}
void yneos(bool a){if(a) cout<<"Yes\n"; else cout<<"No\n";}
template<class T> void vec_out(vector<T> &p){for(int i=0;i<(int)(p.size());i++){if(i) cout<<" ";cout<<p[i];}cout<<"\n";}
template<class T> T min(vector<T> &a){assert(!a.empty());T ans=a[0];for(auto &x:a) chmin(ans,x);return ans;}
template<class T> T max(vector<T> &a){assert(!a.empty());T ans=a[0];for(auto &x:a) chmax(ans,x);return ans;}


void solve();
// oddloop
int main() {
	ios::sync_with_stdio(false);
	cin.tie(nullptr);
	
	int t=1;
	//cin>>t;
	rep(i,t) solve();
}

void solve(){
	ll N,A,B;
    cin>>N>>A>>B;
    string S;
    cin>>S;
    S+="#########";
    vector<int> p;
    rep(i,N){
        int tmp=0;
        while(S.substr(i,3)=="con"){
            tmp++;
            i+=3;
        }
        if(tmp){
            p.push_back(tmp);
            i--;
        }
    }
    int L=2+(N/3)/(A+B);
    vector<int> table(L,-INF);
    table[0]=0;
    Sore(p);
    for(auto x:p){
        vector<pair<int,int>> q;
        rep(i,N){
            if(i*A>x) break;
            q.push_back({i,(x-i*A)/B});
        }
        reverse(all(q));
        for(int i=L-1;i>=0;i--){
            if(table[i]==-INF) continue;
            for(auto y:q){
                int a=i+y.first;
                int b=table[i]+y.second;
                if(a>=L) continue;
                chmax(table[a],b);
            }
        }
    }
    int ans=0;
    //vec_out(table);
    rep(i,L){
        if(table[i]!=-INF){
            int j=table[i];
            if(i>j) chmax(ans,j*2+1);
            else chmax(ans,i*2);
        }
    }
    cout<<ans<<"\n";
}