N=int(input())
Alist=list(map(int,input().split()))
Blist=list(map(int,input().split()))
Clist=list(map(int,input().split()))

Cplus=0
for n in range (1,N-1):
  if Alist[n]-Alist[n-1] == 1:
    Cplus += Clist[Alist[n-1]-1]



print(sum(Blist)+Cplus)