n=int(input())

A=list(map(int,input().split()))
B=list(map(int,input().split()))
C=list(map(int,input().split()))

s=B[0]
for i in range(1,n):
  s+=B[i]
  if A[i-1]==A[i]-1:
    s+=C[A[i-1]-1]

print(s)