N = int(input())
A = list(map(int, input().split()))
B = list(map(int, input().split()))
C = list(map(int, input().split()))
b_dic = {}
for i in range(1, N + 1):
  b_dic[i] = B[i - 1]
c_dic = {}
for i in range(1, N):
  c_dic[i] = C[i - 1]
count=0
br = -1
for a in A:
  count += B[a]
  if br == a - 1:
    count += C[br]
  br = a
print(count)