#include <bits/stdc++.h>
using namespace std;
using ll = long long;

int main(){
    int n, a, b;
    string s;
    cin >> n >> a >> b >> s;
    vector<int> p;
    for(int i = 0; i + 3 <= n; i++){
        if(s.substr(i, 3) != "con")continue;
        int cnt = 0;
        while(i + 3 <= n && s.substr(i, 3) == "con"){
            cnt++;
            i += 3;
        }
        p.push_back(cnt);
    }
    if(a == 1 && b == 1){
        cout << accumulate(p.begin(), p.end(), 0) << '\n';
        return 0;
    }
    vector<int> dp(6001, -(1 << 20));
    dp[0] = 0;
    for(int i = 0; i < p.size(); i++){
        for(int j = 6000 - p[i] / a; j >= 0; j--){
            if(dp[j] == -(1 << 30))continue;
            for(int k = p[i] / a; k >= 0; k--){
                dp[j + k] = max(dp[j + k], dp[j] + (p[i] - a * k) / b);
            }
        }
    }
    int ans = 0;
    for(int j = 6000; j >= 0; j--){
        if(dp[j] >= j - 1)ans = max(ans, j + min(j, dp[j]));
        ans = max(ans, 2 * min(j, dp[j]));
    }
    cout << ans << '\n';
}