using System;
using static System.Console;
using System.Linq;
using System.Collections.Generic;

class Program
{
    static int NN => int.Parse(ReadLine());
    static int[] NList => ReadLine().Split().Select(int.Parse).ToArray();
    public static void Main()
    {
        Solve();
    }
    static void Solve()
    {
        var n = NN * 2;
        var s = ReadLine();
        var a = NList;
        var dp = new long[n + 1][];
        for (var i = 0; i < dp.Length; ++i) dp[i] = Enumerable.Repeat(long.MaxValue / 2, n + 1).ToArray();
        dp[0][0] = 0;
        for (var i = 0; i < n; ++i) for (var j = 0; j < dp[i].Length; ++j)
        {
            if (j - 1 >= 0) dp[i + 1][j - 1] = Math.Min(dp[i + 1][j - 1], dp[i][j] + (s[i] == '(' ? a[i] : 0));
            if (j + 1 < dp[i].Length) dp[i + 1][j + 1] = Math.Min(dp[i + 1][j + 1], dp[i][j] + (s[i] == ')' ? a[i] : 0));
        }
        WriteLine(dp[n][0]);
    }
}