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

satisfaction = 0

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

print(satisfaction)
  