#include <bits/stdc++.h>
#include <atcoder/all>
using namespace std;
using namespace atcoder;
//using mint = modint1000000007;
//const int mod = 1000000007;
//using mint = modint998244353;
//const int mod = 998244353;
const int INF = 1e9;
const long long LINF = 1e18;
#define rep(i, n) for (int i = 0; i < (n); ++i)
#define rep2(i,l,r)for(int i=(l);i<(r);++i)
#define rrep(i, n) for (int i = (n) - 1; i >= 0; --i)
#define rrep2(i,l,r)for(int i=(r) - 1;i>=(l);--i)
#define all(x) (x).begin(),(x).end()
#define allR(x) (x).rbegin(),(x).rend()
#define P pair<int,int>
template<typename A, typename B> inline bool chmax(A & a, const B & b) { if (a < b) { a = b; return true; } return false; }
template<typename A, typename B> inline bool chmin(A & a, const B & b) { if (a > b) { a = b; return true; } return false; }
int op(int a, int b) { return min(a, b); }
int e() { return INF; }
int main() {
	ios::sync_with_stdio(false);
	cin.tie(nullptr);
	int n; cin >> n;
	string s; cin >> s;
	int r, m; cin >> r >> m;
	if (n % 2 != 0) {
		cout << -1 << endl;
		return 0;
	}
	vector<int>v(2 * n + 1);
	rep(i, n) v[i + 1] = v[i] + (s[i] == '(' ? 1 : -1);
	rep(i, n) v[n + i + 1] = v[n + i] + (s[i] == '(' ? 1 : -1);
	segtree<int, op, e>seg(v);
	long long ans = LINF;
	rrep(l, n + 1) {
		auto get = seg.prod(l, l + n + 1);
		int cnt = (v[l] - get + 1) / 2;
		long long cost = cnt * m;
		long long x = v[l + n] + 2 * cnt;
		cost += (x - v[l]) / 2 * m;
		cost += (n - l) * r;
		chmin(ans, cost);
	}
	cout << ans << endl;
	return 0;
}