n = int(input())
s = input()
a = list(map(int, input().split()))

max_score = 0

for sign_r in range(-1, 2, 2):
    sign_b = -sign_r
    score = 0
    for i in range(0, n):
        if s[i] == 'R':
            score += sign_r * a[i]
        else:
            score += sign_b * a[i]
        max_score = max(max_score, score)

        if score < 0:
            score = 0

print(max_score)