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

inf = 10 ** 18
M = 2 * N
dp = [[inf] * (M + 5) for i in range(M + 5)]
dp[0][0] = 0
for i in range(M):
    for j in range(M):
        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:
            if j:
                dp[i + 1][j - 1] = min(dp[i + 1][j - 1], dp[i][j])
            dp[i + 1][j + 1] = min(dp[i + 1][j + 1], dp[i][j] + A[i])
                 
print(dp[M][0])