N = int(input())

A_list = list(input().split())
A_list_int = [int(s) for s in A_list]

B_list = list(input().split())
B_list_int = [int(s) for s in B_list]

C_list = list(input().split())
C_list_int = [int(s) for s in C_list]

Answer = []

for i in range(0, N):
  Answer.append(B_list_int[A_list_int[i] - 1])
  if i != N and i != 0:
      if A_list_int[i - 1] == A_list_int[i] - 1:
          Answer.append(C_list_int[i - 1])

print(sum(Answer))