#include <iostream>
#include <vector>
#include <string>
#include <algorithm>
using namespace std;

int main(){
    int N, A, B;
    cin >> N >> A >> B;
    string S;
    cin >> S;
    
    vector<int> rle(0);
    int concnt = 0;
    int now_idx = 0;
    while(true){
        if (now_idx >= N - 2){
            if (concnt >= 1){
                rle.push_back(concnt);
            }
            break;
        }
        else if (S.substr(now_idx, 3) == "con"){
            now_idx += 3;
            concnt++;
        }
        else{
            now_idx++;
            if (concnt >= 1){
                rle.push_back(concnt);
            }
            concnt = 0;
        }
    }
    int INF = 50000;
    int len = rle.size();
    vector<int> dp1(8336, INF * -1);
    vector<int> dp2(8336, INF * -1);
    dp1[0] = 0;
    for (int i = 0; i < len; i++){
        for (int j = 0; j < 8336; j++){
            for (int k = 0; k <= (rle[i] / A); k++){
                if (j + k >= 8336) continue;
                dp2[j + k] = max(dp2[j + k], dp1[j] + (rle[i] - A * k) / B);
            }
        }
        for (int j = 0; j < 8336; j++){
            dp1[j] = dp2[j];
            dp2[j] = INF * -1;
        }
    }
    int ans = 0;
    for (int j = 0; j < 8336; j++){
        if (dp1[j] >= j - 1) ans = max(ans, 2 * j - 1);
        if (dp1[j] >= j) ans = max(ans, 2 * j);
    }
    cout << ans << endl;
}