N = int(input())
S = input()
A = list(map(int, input().split()))
C = [0] * (N + 1)
for i in range(N):
    if S[i] == "R":
        C[i + 1] = C[i] + A[i]
    else:
        C[i + 1] = C[i] - A[i]

maxC = 0
minC = 0
ans = 0
for i in range(1, N + 1):
    ans = max(ans, abs(C[i] - maxC), abs(C[i] - minC))
    maxC = max(maxC, C[i])
    minC = min(minC, C[i])
print(ans)