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

ans = sum(c[a[i] - 1] for i in range(n - 1) if a[i + 1] - a[i] == 1)
print(ans + sum(b))