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

total = 0
pos = 0
while pos < N:
  total += B[A[pos] - 1]
  if A[pos + 1] - A[pos] == 1:
    total += C[A[pos + 1] - 2]
  pos += 1
print(total)
   
