N = int(input())
A = list(map(int, input().split()))
B = list(map(int, input().split()))
C = list(map(int, input().split()))
 
manzoku = 0
prev = 0
 
for a in A:
  manzoku += B[a-1]
  if prev == a:
    manzoku += C[prev-1]
  prev = a
print(manzoku)