# -*- coding: utf-8 -*-
n = int(input())
a = list(map(int, input().split()))
b = list(map(int, input().split()))
c = list(map(int, input().split()))
eat = 0
mae = n
for i in a:
    eat += b[i-1]
    if mae < n:
        eat +=c[mae-1]
    mae = i
print(eat)