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

ans=0
prev=None
for i in range(N):
	a=A[i]
	ans+=B[a-1]
	if prev is None:
		pass
	elif prev+1==a:
		ans+=C[prev-1]
	prev=a

print ans