N = int(input())
A = tuple(int(x) for x in input().split())
B = tuple(int(x) for x in input().split())
C = tuple(int(x) for x in input().split())

satisfy = sum(B)

for i in range(len(A)-1):
  if A[i+1]-A[i] is 1:
    satisfy += C[A[i]]

print(satisfy)