N = int(input())
S = "0"+input().strip()
A = [0]+list(map(int,input().split()))
INFTY = 10**12+100
dp = [[INFTY for _ in range(2*N+1)] for _ in range(2*N+1)]
if S[1]=="(":
    dp[1][1] = 0
else:
    dp[1][1] = A[1]
for i in range(2,2*N+1):
    for j in range(i+1):
        if j==0:
            dp[i][0] = dp[i-1][1]
            if S[i]=="(":
                dp[i][0] += A[i]
        elif j==i:
            dp[i][i] = dp[i-1][i-1]
            if S[i]==")":
                dp[i][i] += A[i]
        else:
            if S[i]=="(":
                dp[i][j] = min(dp[i-1][j-1], dp[i-1][j+1]+A[i])
            else:
                dp[i][j] = min(dp[i-1][j+1], dp[i-1][j-1]+A[i])
print(dp[2*N][0])