Problem3311--Resort

3311: Resort

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Time Limit : 2.000 sec  Memory Limit : 256 MiB

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Description

time limit per test
2 seconds
memory limit per test
256 megabytes
input
standard input
output
standard output

Valera's finally decided to go on holiday! He packed up and headed for a ski resort.

Valera's fancied a ski trip but he soon realized that he could get lost in this new place. Somebody gave him a useful hint: the resort has n objects (we will consider the objects indexed in some way by integers from 1 to n), each object is either a hotel or a mountain.

Valera has also found out that the ski resort had multiple ski tracks. Specifically, for each object v, the resort has at most one object u, such that there is a ski track built from object u to object v. We also know that no hotel has got a ski track leading from the hotel to some object.

Valera is afraid of getting lost on the resort. So he wants you to come up with a path he would walk along. The path must consist of objects v1,v2,...,vk (k≥1) and meet the following conditions:

  1. Objects with numbers v1,v2,...,vk-1 are mountains and the object with number vk is the hotel.
  2. For any integer i (1≤i<k), there is exactly one ski track leading from object vi. This track goes to object vi+1.
  3. The path contains as many objects as possible (k is maximal).

Help Valera. Find such path that meets all the criteria of our hero!

Input

The first line contains integer n (1≤n≤105) − the number of objects.

The second line contains n space-separated integers type1,type2,...,typen − the types of the objects. If typei equals zero, then the i-th object is the mountain. If typei equals one, then the i-th object is the hotel. It is guaranteed that at least one object is a hotel.

The third line of the input contains n space-separated integers a1,a2,...,an (0≤ai≤n) − the description of the ski tracks. If number ai equals zero, then there is no such object v, that has a ski track built from v to i. If number ai doesn't equal zero, that means that there is a track built from object ai to object i.

Output

In the first line print k − the maximum possible path length for Valera. In the second line print k integers v1,v2,...,vk − the path. If there are multiple solutions, you can print any of them.

Examples
Input
5
0 0 0 0 1
0 1 2 3 4
Output
5
1 2 3 4 5
Input
5
0 0 1 0 1
0 1 2 2 4
Output
2
4 5
Input
4
1 0 0 0
2 3 4 2
Output
1
1

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