from math import inf


def main():
    N = int(input())
    S = input()
    A = list(map(int, input().split()))
    dp_table = [[inf for _ in range(N + 1)] for _ in range(N * 2 + 1)]
    dp_table[0][0] = 0
    for idx in range(2 * N):
        for left_over_n in range(N + 1):
            if S[idx] == "(":
                if left_over_n + 1 <= N:
                    dp_table[idx + 1][left_over_n + 1] = min(
                        dp_table[idx + 1][left_over_n + 1],
                        dp_table[idx][left_over_n]
                    )
                if left_over_n >= 1:
                    dp_table[idx + 1][left_over_n - 1] = min(
                        dp_table[idx + 1][left_over_n - 1],
                        dp_table[idx][left_over_n] + A[idx]
                    )
            elif S[idx] == ")":
                if left_over_n + 1 <= N:
                    dp_table[idx + 1][left_over_n + 1] = min(
                        dp_table[idx + 1][left_over_n + 1],
                        dp_table[idx][left_over_n] + A[idx]
                    )
                if left_over_n >= 1:
                    dp_table[idx + 1][left_over_n - 1] = min(
                        dp_table[idx + 1][left_over_n - 1],
                        dp_table[idx][left_over_n]
                    )
            else:
                raise ValueError
    print(dp_table[-1][0])


if __name__ == "__main__":
    main()