How to remove a counted nested div?

Question

Internet advertising

I want to remove the ad block from Yandex mail.
There is a div of the left panel


. A pack of divs is nested in it. An advertising DIV with a permanently changing class, fourth from the end. That's what needs to be blocked.
Adblocks don't help. class and data-key are constantly changing.

Answer 1

Nth-child() can be