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

dp=[[10**18 for i in range(n*2+1)] for j in range(2*n+1)]
dp[0][0]=0 

for i in range(n*2):
	for j in range(n*2):
		if dp[i][j]!=10**18:
			if S[i]=='(':
				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])
				dp[i+1][j+1]=min(dp[i+1][j+1],dp[i][j]+A[i])

print(dp[n*2][0])