N = int(input())
A = list(map(lambda a: int(a), input().split(" ")))
B = list(map(lambda b: int(b), input().split(" ")))
C = list(map(lambda c: int(c), input().split(" ")))

satis = 0

for i in range(len(A)):
  satis += B[A[i]]
  if i >= 1 and A[i] - A[i-1] == 1:
    satis += C[i-1]

print(satis)