num = int(input())
a = list(map(int, input().split()))
b = list(map(int, input().split()))
c = list(map(int, input().split()))
sum = 0

for i in range(num):
	if i == 0:
		sum += b[a[i]]
	else:
		sum += b[a[i]]
		if (a[i]-1) == a[i-1]:
			sum += c[i-1]

print(sum)
          