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

point = 0

for i in range(N):
  no_food = A[i]
  point += B[no_food - 1]
  if i != 0:
    if no_food - A[i - 1] == 1:
      point += C[no_food - 2]

print point