Write a function that properly extracts a "Product ID" from a URL. This ID is encoded in the URL in the following way:
- It immediately follows
-p- - It is terminated with
-
Your function should return a string.
For example, given the following URL example.com/product-p-8099-index.html, your function should return '8099', as it satisfies the above rules.
Given example.com/products/gift-p-door801933-edit.html, your function should return 'door801933'.