n = int(input())
s = input()
a = list(map(int, input().split()))
r = [0] * (n + 1)
b = [0] * (n + 1)
ans = 0
for i in range(n):
    r[i + 1] = r[i]
    b[i + 1] = b[i]
    if s[i] == 'R':
        r[i + 1] = r[i] + a[i]
    else:
        b[i + 1] = b[i] - a[i]
    ans = max(ans, abs(r[i + 1] - b[i + 1]))
print(ans)