I have two question. Can anyone help me? Thanks very much!

1. In the problem description, the permutation's name is $$$p$$$, but in the editorial the array's name is $$$a$$$. So what's that?

2. If we consider $$$a$$$ as $$$p$$$. The first paragraph of the editorial shows that if we choose a subset of $$$a_i \gt a_{i+1}$$$, then the subsequence is valid. But the last paragraph of the editorial says we should count the situation that $$$a_i \lt a_{i+1}$$$. Why's that?

Sorry for my bad English. :)

bestial-42-centroids can you explain this?

I'm really need help!