#!/usr/bin/env python

from collections import deque, defaultdict
import itertools as ite
import sys
import math
import decimal

sys.setrecursionlimit(1000000)

INF = 10 ** 18
MOD = 10 ** 9 + 7

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

ans = sum(B)
for i in range(N - 1):
    if A[i] + 1 == A[i + 1]:
        ans += C[A[i] - 1]

print ans