n = int(input())
A = list(map(int, input().split()))
B = list(map(int, input().split()))
C = list(map(int, input().split()))
cnt = 0
b = 0
for a in A:
  cnt += B[a-1]
  if a == b+1:
    cnt += C[a-2]
  b = a
print(cnt)
