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)))