N = int(input())
A = list(map(int, input().split(" ")))
B = list(map(int, input().split(" ")))
C = list(map(int, input().split(" ")))
ans = B[A[0] - 1]
for i in range(1, N):
  ans += B[A[i] - 1]
  if A[i - 1] + 1 == A[i]:
    ans += C[A[i] - 1]
  
print(ans)