'''
 Author: fuad Ashraful Mehmet
 University of Asia Pacific
 created :09 Sep 2019 7.33 PM
 Category :   from At Coder

 Problem:https:  
'''

 
 

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


ans=sum(B)


for i in range(n-1):

	if A[i+1]==A[i]+1:
		ans+=C[A[i]-1]



#fuck python if you can its just owsam