#pragma region
/*
\(^o^)/
import sys
私は人間です．



吾輩はやれば出来る子である.

　　　　∩ ∩
　　　（´･ω･）
　　 ＿|　⊃／(＿＿_
　／　└-(＿＿＿_／
　￣￣￣￣￣￣￣

　やる気はまだない.

　　 ⊂⌒／ヽ-、＿_
　／⊂_/＿＿＿＿ ／
　￣￣￣￣￣￣￣
*/
#include<algorithm>
#include<array>
#include<bitset>
#include<cassert>
#include<chrono>
#include<cinttypes>
#include<climits>
#include<cmath>
#include<complex>
#include<cstdio>
#include<cstring>
#include<deque>
#include<functional>
#include<iomanip>
#include<iostream>
#include<iterator>
#include<limits>
#include<map>
#include<numeric>
#include<queue>
#include<random>
#include<set>
#include<sstream>
#include<stack>
#include<string>
#include<tuple>
#include<type_traits>
#include<unordered_map>
#include<unordered_set>
#include<utility>
#include<vector>
using namespace std;
struct Init{Init(){std::cin.tie(0); ios::sync_with_stdio(false); cout << setprecision(20) << fixed;}}init;
using ll = long long;
using ull = unsigned long long;
using ld = long double;
#define all(x) begin((x)), end((x))
#define pb push_back
#define mp make_pair
#define mt make_tuple
#define uq(v) v.erase(unique(begin(v), end(v)), end(v))
#define _overload4(_1,_2,_3,_4,name,...) name
#define _overload3(_1,_2,_3,name,...) name
#define _rep1(n) for(int i=0;i<n;++i)
#define _rep2(i,n) for(int i=0;i<n;++i)
#define _rep3(i,a,b) for(int i=a;i<b;++i)
#define _rep4(i,a,b,c) for(int i=a;i<b;i+=c)
#define rep(...) _overload4(__VA_ARGS__,_rep4,_rep3,_rep2,_rep1)(__VA_ARGS__)
#define _rrep1(n) for(int i=(n)-1;i>=0;i--)
#define _rrep2(i,n) for(int i=(n)-1;i>=0;i--)
#define _rrep3(i,a,b) for(int i=(b)-1;i>=(a);i--)
#define _rrep4(i,a,b,c) for(int i=a+(b-a-1)/c*c;i>=a;i-=c)
#define rrep(...) _overload4(__VA_ARGS__,_rrep4,_rrep3,_rrep2,_rrep1)(__VA_ARGS__)
template<class T> using pq = priority_queue<T>;
template<class T> using pq_g = priority_queue<T, vector<T>, greater<T>>;
template<class T> bool chmax(T &a, const T &b){if(a < b){a = b; return 1; } return 0;}
template<class T> bool chmin(T &a, const T &b){if(a > b){a = b; return 1; } return 0;}
template<class T> auto min(const T& a){ return *min_element(all(a)); }
template<class T> auto max(const T& a){ return *max_element(all(a)); }
constexpr ull INF = (1ULL << 61) + (1ULL << 30);
constexpr int inf = (1 << 30);
constexpr ld EPS = 1e-9;
constexpr int dx[] = {1, 0, -1, 0, 1, 1, -1, -1};
constexpr int dy[] = {0, 1 ,0, -1, 1, -1, 1, -1};

#pragma endregion

template<typename S2, typename Op, typename E, typename F2, typename Mapping, typename Composition, typename Id>
struct LambdaActedMonoid{
    using S = S2;
    using F = F2;
    S op(const S &a, const S &b) const {return _op(a, b);}
    S e() const {return _e();}
    S mapping(const S &x, const F &f) const {return _mapping(x, f);}
    F composition(const F &f, const F &g) const {return _composition(f, g);}
    F id() const {return _id();}
    
    LambdaActedMonoid(Op _op, E _e, Mapping _mapping, Composition _composition,Id _id): _op(_op), _e(_e), _mapping(_mapping), _composition(_composition), _id(_id){}

private:
    Op _op;
    E _e;
    Mapping _mapping;
    Composition _composition;
    Id _id;
};

template<typename Op, typename E, typename Mapping, typename Composition, typename Id>
LambdaActedMonoid(Op _op, E _e, Mapping _mapping, Composition _composition, Id _id) -> LambdaActedMonoid<decltype(_e()), Op, E, decltype(_id()), Mapping, Composition, Id>;

template<typename ActedMonoid>
struct LazySegmentTree{
    using S = typename ActedMonoid::S;
    using F = typename ActedMonoid::F;

private:
    ActedMonoid m;
    int n{}, sz{}, height{};
    vector<S> dat;
    vector<F> lazy;

    inline void update(int k){
        dat[k] = m.op(dat[2 * k + 0], dat[2 * k + 1]);
    }

    inline void all_apply(int k, const F &x){
        dat[k] = m.mapping(dat[k], x);
        if(k < sz) lazy[k] = m.composition(lazy[k], x);
    }

    inline void propagate(int k){
        if(lazy[k] != m.id()){
            all_apply(2 * k + 0, lazy[k]);
            all_apply(2 * k + 1, lazy[k]);
            lazy[k] = m.id();
        }
    }

public:
    LazySegmentTree() = default;
    explicit LazySegmentTree(ActedMonoid m, int n): m(m), n(n){
        sz = 1;
        height = 0;
        while(sz < n) sz <<= 1, ++height;
        dat.assign(2 * sz, m.e());
        lazy.assign(2 * sz, m.id());
    }
    explicit LazySegmentTree(ActedMonoid m, const vector<S> &v): LazySegmentTree(m, v.size()){
        build(v);
    }

    void build(const vector<S> &v){
        assert(n == (int)v.size());
        for(int k = 0; k < n; ++k) dat[k + sz] = v[k];
        for(int k = sz - 1; k > 0; --k) update(k);
    }

    void set(int k, const S &x){
        k += sz;
        for(int i = height; i > 0; --i) propagate(k >> i);
        dat[k] = x;
        for(int i = 1; i <= height; ++i) update(k >> i);
    }

    S get(int k){
        k += sz;
        for(int i = height; i > 0; --i) propagate(k >> i);
        return dat[k];
    }

    S operator[](int k){return get(k);}

    S query(int l, int r){
        if(l >= r) return m.e();
        l += sz;
        r += sz;
        for(int i = height; i > 0; --i){
            if(((l >> i) << i) != l) propagate(l >> i);
            if(((r >> i) << i) != r) propagate((r - 1) >> i);
        }
        S L = m.e(), R = m.e();
        for(; l < r; l >>= 1, r >>= 1){
            if(l & 1) L = m.op(L, dat[l++]);
            if(r & 1) R = m.op(dat[--r], R);
        }
        return m.op(L, R);
    }

    S all_query() const {return dat[1];}

    void apply(int k, const F &f){
        k += sz;
        for(int i = height; i > 0; --i) propagate(k >> i);
        dat[k] = m.mapping(dat[k], f);
        for(int i = 1; i <= height; ++i) update(k >> i);
    }

    void apply(int l, int r, const F &f){
        if(l >= r) return;
        l += sz;
        r += sz;
        for(int i = height; i > 0; --i){
            if(((l >> i) << i) != l) propagate(l >> i);
            if(((r >> i) << i) != r) propagate((r - 1) >> i);
        }
        int l2 = l, r2 = r;
        for(; l < r; l >>= 1, r >>= 1){
            if(l & 1) all_apply(l++, f);
            if(r & 1) all_apply(--r, f);
        }
        l = l2, r = r2;
        for(int i = 1; i <= height; ++i){
            if(((l >> i) << i) != l) update(l >> i);
            if(((r >> i) << i) != r) update((r - 1) >> i);
        }
    }

    template<typename C>
    int find_first(int l, const C &check){
        if(l >= n) return n;
        l += sz;
        for(int i = height; i > 0; --i) propagate(l >> i);
        S sum = m.e();
        do{
            while((l & 1) == 0) l >>= 1;
            if(check(m.op(sum, dat[l]))){
                while(l < sz){
                    propagate(l);
                    l <<= 1;
                    auto nxt = m.op(sum, dat[l]);
                    if(not check(nxt)){
                        sum = nxt;
                        ++l;
                    }
                }
                return l + 1 - sz;
            }
            sum = m.op(sum, dat[l++]);
        }while((l & -l) != l);
        return n;
    }

    template<typename C>
    int find_last(int r, const C &check){
        if(r <= 0) return -1;
        r += sz;
        for(int i = height; i > 0; --i) propagate((r - 1) >> i);
        S sum = m.e();
        do{
            --r;
            while(r > 1 && (r & 1)) r >>= 1;
            if(check(m.op(dat[r], sum))){
                while(r < sz){
                    propagate(r);
                    r = (r << 1) + 1;
                    auto nxt = m.op(dat[r], sum);
                    if(not check(nxt)){
                        sum = nxt;
                        --r;
                    }
                }
                return r - sz;
            }
            sum = m.op(dat[r], sum);
        }while((r & -r) != r);
        return -1;
    }
};


auto op1 = [](ll a, ll b){return min(a, b); };
auto e1 = []() { return (ll)INF; };
auto mapping1 = [](ll x, ll f){return x + f;};
auto composition1 = [](ll f, ll g){return f + g;};
auto id1 = [](){return 0LL;};





int main(){
    int N; cin >> N;
    string S; cin >> S;
    ll R, M; cin >> R >> M;
    if(N & 1){
        cout << "-1\n";
        return 0;
    }
    ll ans = INF;
    LazySegmentTree seg(LambdaActedMonoid(op1, e1, mapping1, composition1, id1), 2 * N);
    int cutkari = 0;
    rep(i, N){
        if(S[i] == '(') ++cutkari;
        else --cutkari;
        seg.set(N + i, cutkari);
    }
    int cur1 = max((-seg.query(N, N * 2) + 1) / 2, 0LL);
    ans = (cur1 + (seg[2 * N - 1] + cur1 * 2) / 2) * M;
    rep(i, 1, N){
        seg.apply(N - i, 2 * N - i, (S[N - i] == '(' ? 1 : -1));
        int cur = max((-seg.query(N - i, N * 2 - i) + 1) / 2, 0LL);
        ans = min(ans, R * i + (cur + (seg[2 * N - 1] + cur * 2) / 2) * M);
    }
    cout << ans << "\n";
}