import numpy as np

N = int(input())
A = list(map(int, input().split()))
B = list(map(int, input().split()))
C = list(map(int, input().split()))

r = np.sum(B)
for i in range(N-1):
  if A[i] + 1 == A[i + 1]:
    r += C[A[i]]

print(r)