#include <bits/stdc++.h>
using namespace std;
#define all(p) p.begin(), p.end()
#define rep(i, a, b) for (int i = (int)(a); i < (int)(b); i++)
using ll = long long;

#include <atcoder/segtree>
struct F{
    int sum = 0;
    int mim = 0;
};

F op(F l, F r){
    l.mim = min(l.mim, l.sum + r.mim);
    l.sum += r.sum;
    return l;
}
F e(){
    return F{};
}

int main(){
    int N;
    cin >> N;
    string S;
    cin >> S;
    ll R, M;
    cin >> R >> M;
    if (N & 1){
        cout << "-1\n";
        return 0;
    }
    vector<F> base(N);
    rep(i, 0, N){
        if (S[i] == '(') base[i] = {1, 0};
        else base[i] = {-1, -1};
    }
    rep(i, 0, N) base.push_back(base[i]);
    atcoder::segtree<F, op, e> seg(base);
    ll ans = (1ll << 60);
    rep(i, 0, N){
        auto tmp = seg.prod(N - i, 2 * N - i);
        int z = (1 - tmp.mim) / 2;
        z += abs(tmp.sum + z * 2) / 2;
        ans = min(ans, R * i + z * M);
    }
    cout << ans << "\n";
}