N=int(input())
l=list(input())
a=list(map(int,input().split()))
rb,br=[0]*(N+1),[0]*(N+1)
R,B=0,0
for i in range(N):
   if l[i]=="R":
      R+=a[i]
   else:
      B+=a[i]
   rb[i+1]=R-B
   br[i+1]=B-R
print(max(max(rb)-min(rb),max(br)-min(br)))