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

ans = minv = maxv = v = 0

for i in range(n):
    if s[i] == "R":
        v += a[i]
    else:
        v -= a[i]

    ans = max(ans, abs(v - minv))
    ans = max(ans, abs(v - maxv))
    minv = min(minv, v)
    maxv = max(maxv, v)

print(ans)