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

for i in range(n):
    if s[i] == "R":
        continue
    else:
        A[i] *= -1

cumA = [0] * (n + 1)

for i in range(n):
    cumA[i + 1] = A[i] + cumA[i]

plus = 0
minus = 0
pre_plus = 0
pre_minus = 0
for i in range(1, n + 1):
    score_plus = cumA[i] - cumA[pre_plus]
    score_minus = cumA[i] - cumA[pre_minus]
    if score_plus < 0:
        pre_plus = i
    if score_minus > 0:
        pre_minus = i
    plus = max(plus, score_plus)
    minus = min(minus, score_minus)
print(max(plus, -minus))