N = int(input())
A = list(map(int,input().split()))
B = list(map(int,input().split()))
C = list(map(int,input().split()))
total = 0

for j in range(N):
  total = total + B[j]

for i in range(N-1):
  if i > 0 and A[i] == A[i-1] + 1:
    Z = A[i-1]
    total = total +C[Z-1]
print(total)
