INF = 1 << 60
N = int(input())
S = input()
A = list(map(int, input().split()))

sz = 2 * N + 1
dp = [INF] * sz
dp[0] = 0
for i, (c, a) in enumerate(zip(S, A)):
    pp = [INF] * sz
    dp, pp = pp, dp
    for j in range(2 * N):
        if pp[j] == INF: continue

        if c == '(':
            dp[j+1] = min(dp[j+1], pp[j])

            if j > 0:
                dp[j-1] = min(dp[j-1], pp[j] + a)
        elif c == ')':
            if j > 0:
                dp[j-1] = min(dp[j-1], pp[j])

            dp[j+1] = min(dp[j+1], pp[j] + a)

ans = dp[0]
print(ans)