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

inf = 10 ** 20
dp = [[inf] * (N + 1) for _ in range(2 * N + 1)]
dp[0][0] = 0

for i in range(N + N):
    for j in range(N + 1):
        if S[i] == "(":
            if j < N:
                dp[i + 1][j + 1] = min(dp[i + 1][j + 1],dp[i][j])
            if j > 0:
                dp[i + 1][j - 1] = min(dp[i + 1][j - 1],dp[i][j] + A[i])
        else:
            if j > 0:
                dp[i + 1][j - 1] = min(dp[i + 1][j - 1],dp[i][j])
            if j < N:
                dp[i + 1][j + 1] = min(dp[i + 1][j + 1],dp[i][j] + A[i])
print(dp[-1][0])