n = int(input())

a = []
for i in range(n):
  a.append(int(input()))

b = []
for i in range(n):
  b.append(int(input()))

c = []
for i in range(n - 1):
  c.append(int(input()))

answer = 0

for x in range(len(a)):
  if x >= 1:
    if a[x-1] < len(c) + 1:
      answer += c[a[x - 1] - 1]
  answer += b[a[x] - 1]

print(answer)