INF=pow(2,61)-1
N=int(input())
S=input()
A=list(map(int,input().split()))
dp=[[INF]*(N*2+2) for i in range(N*2+1)]
dp[0][0]=0
for i in range(N*2):
	for j in range(N*2+1):
		if dp[i][j]>=INF:
			continue
		if S[i]=="(":
			dp[i+1][j+1]=min(dp[i][j],dp[i+1][j+1])
			dp[i+1][j-1]=min(dp[i][j]+A[i],dp[i+1][j-1])
		else:
			dp[i+1][j+1]=min(dp[i][j]+A[i],dp[i+1][j+1])
			dp[i+1][j-1]=min(dp[i][j],dp[i+1][j-1])
print(dp[-1][0])