n=int(input())
*a,=map(int,input().split())
*b,=map(int,input().split())
*c,=map(int,input().split())
ans=0
for i in range(n):
	ans += b[i]
for  i in range(n-1):
	if a[i+1]==a[i]+1:
		ans += c[a[i]-1]
print(ans)