N = int(input())
S = input()
a = list(map(int, input().split()))

ans=-10**18
for i in range(N):
    for j in range(i + 1, N):
        r = 0
        b=0
        for k in range(i, j + 1):
            if S[k] == "R":
                r += a[k]
            else:
                b += a[k]
        ans = max(ans, abs(r - b))
print(ans)