# coding: utf-8
import sys

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


count = 0

for i in xrange(n):
    #print i,a[i], b[a[i]-1]  
    count += b[a[i]-1]
    if i > 0 and a[i] == a[i-1] + 1:
        count += c[a[i-1]-1]
        #print c[a[i-1]-1]
print count