#include<bits/stdc++.h>
namespace {
using namespace std;
#define rep(i,n) for(int i = 0; i < (int)(n); i++)
#define rrep(i,n) for(int i = (int)(n) - 1; i >= 0; i--)
#define all(x) begin(x), end(x)
#define rall(x) rbegin(x), rend(x)
template<class T> bool chmax(T& a, const T& b) { if (a < b) { a = b; return true; } else return false; }
template<class T> bool chmin(T& a, const T& b) { if (b < a) { a = b; return true; } else return false; }
using ll = long long;
using P = pair<int,int>;
using VI = vector<int>;
using VVI = vector<VI>;
using VL = vector<ll>;
using VVL = vector<VL>;

} int main() {
  ios::sync_with_stdio(false);
  cin.tie(0);
  int n;
  string s;
  cin >> n >> s;
  constexpr long long INF = 1002003004005006007;
  VL dp{0};
  rep(i, 2 * n) {
    int a;
    cin >> a;
    VL ndp(i + 2, INF);
    rep(j, i + 1) {
      if (j) chmin(ndp[j-1], dp[j] + (s[i] != ')') * a);
      chmin(ndp[j+1], dp[j] + (s[i] != '(') * a);
    }
    swap(dp, ndp);
  }
  cout << dp[0] << '\n';
}