n = input()
sated= 0
eat = list(map(int, input().split(' ')))
sat = list(map(int, input().split(' ')))
aft = list(map(int, input().split(' ')))

for i in range(int(n)):
    sated += sat[eat[i]-1]
    if i == 0:
      continue
    if eat[i] == eat[i-1]+1:
        sated += aft[i]
print(sated)