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

A.insert(0,0)
B.insert(0,0)
C.insert(0,)
manzoku = 0
prev = 0
 
for a in A:
  manzoku += B[a]
  if prev != 0 and prev != N:
    manzoku += C[prev]
  prev = a
print(manzoku)