#!/usr/bin/env python
# -*- coding: utf-8 -*-

N = int(input())
A = [int(x) for x in input().split()]
B = [int(x) for x in input().split()]
C = [int(x) for x in input().split()]
happiness = 0

for i in range(0, N, i++):
  if(A[N-1]==A[N]-1):
    happiness += (B[A[N]]+C[N-1])
  else:
    happiness += B[A[N]]
print(happiness)