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

manzoku=0;

for i in range(len(A)):
	a=A[i]
	manzoku+=B[a-1]
	if i+1<n and A[i+1]-A[i]==1 :
		manzoku+=C[a-1]
	i+=1
print(manzoku)