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

sum=0
for i in range(n):
  sum=sum+b[a[i]]
  if i>0 | a[i-1] == a[i]+1:
    sum=sum+c[a[i-1]]