"""

Rの総和
Bの総和

で、R,B 片方が正・もう片方が負の寄与


"""

import sys
from sys import stdin

N = int(stdin.readline())
n = N
S = stdin.readline()[:-1]

a = list(map(int,stdin.readline().split()))

nmin = 0
now = 0
ans = 0

for i in range(n):

    if S[i] == "R":
        now += a[i]
    else:
        now -= a[i]

    ans = max(ans , now - nmin)
    nmin = min(nmin,now)

nmin = 0
now = 0
    
for i in range(n):

    if S[i] == "R":
        now -= a[i]
    else:
        now += a[i]

    ans = max(ans , now - nmin)
    nmin = min(nmin,now)

print (ans)