n = int(input())

a = list(map(int,input().split()))
b = list(map(int,input().split()))
c = list(map(int,input().split()))

ans = 0
for i in range(n):
  if i >= 1 and a[i - 1] + 1 == a[i]:
    ans += c[i - 1]
  ans += b[i]

print(ans)