Hazel rule to delete ResearchGate pdf cover pages

I download a load of academic papers in as PDFs from ResearchGate, since that's often the only place a free version of a paper is available.  Unfortunately, ResearchGate prepend downloaded PDFs with a branded cover page, which I obviously don't want.

On MacOS, it's easy enough to manually delete pages from a PDF using Preview.  But with a bit of help from Hazel, it's possible to automate it.