n = int(input())
s = input()
a = list(map(int, input().split()))

INF = 10 ** 18
dp = [[INF] * (2 * n + 1) for _ in range(2 * n + 1)]

dp[0][0] = 0

for i in range(2 * n):
    for j in range(2 * n + 1):
        if dp[i][j] == INF:
            continue
        if s[i] == '(':
            dp[i + 1][j + 1] = min(dp[i + 1][j + 1], dp[i][j])
            if j:
                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:
                dp[i + 1][j - 1] = min(dp[i + 1][j - 1], dp[i][j])

print(dp[2 * n][0])