n=int(input())
orders = [ int(_) for _ in input().split()]
Bn = [ int(_) for _ in input().split()]
Cn = [ int(_) for _ in input().split()]

utility = 0
for i in range(orders):
  utility += Bn[orders[i]-1]
  if i!=0 and orders[i-1] +1 == orders[i]:
    utility += Cn[i-1]

print(utility)
