n = int(input())
S = input()
A = list(map(int, input().split()))

INF = 10**18
DP = [[INF for _ in range(2 * n + 1)] for _ in range(2 * n + 1)]
DP[0][0] = 0
for i in range(2 * n):
    s = S[i]
    for j in range(2 * n + 1):
        if DP[i][j] != INF:
            if s == '(':
                DP[i + 1][j + 1] = min(DP[i + 1][j + 1], DP[i][j])
                if j - 1 >= 0:
                    DP[i + 1][j - 1] = min(DP[i + 1][j - 1], DP[i][j] + A[i])
            else:
                DP[i + 1][j + 1] = min(DP[i + 1][j + 1], DP[i][j] + A[i])
                if j - 1 >= 0:
                    DP[i + 1][j - 1] = min(DP[i + 1][j - 1], DP[i][j])
print(DP[2 * n][0])