N=int(input())
S=list(input())
A=list(map(int,input().split()))
dp=[[10**18]*(N+1) for _ in range(2*N+1)]
dp[0][0]=0
for i in range(2*N):
    for j in range(N+1):
        if(S[i]=="("):
            if(j<N):
                dp[i+1][j+1]=min(dp[i+1][j+1],dp[i][j])
            if(0<j):
                dp[i+1][j-1]=min(dp[i+1][j-1],dp[i][j]+A[i])
        else:
            if(j<N):
                dp[i+1][j+1]=min(dp[i+1][j+1],dp[i][j]+A[i])
            if(0<j):
                dp[i+1][j-1]=min(dp[i+1][j-1],dp[i][j])
print(dp[2*N][0])