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

L1=[]
L2=[]
for i in range(n):
  if s[i]=='R':
    L1.append(a[i])
    L2.append(-a[i])
  else:
    L1.append(-a[i])
    L2.append(a[i])

ans1=[]
ans2=[]
ct1=0
ct2=0
for i in range(n):
  ct1+=L1[i]
  if ct1<0:
    ct1=0
  ans1.append(ct1)
  ct2+=L2[i]
  if ct2<0:
    ct2=0
  ans2.append(ct2)

print(max(ans1+ans2))