Excel Formula - Delete rom IF NOT ".pdf"

Hello,

I am having the most troubling of times trying to find the google answer to this question. I stumbled upon this forum and many of you seem extremely well versed in Excel formulas/macros. I have a spreadsheet with a single column of data (A1:A4000) containing a bunch of web "GET" requests. I want to delete every row that does not contain ".pdf" in the GET request line. Is there a formula I can use?

I don't care if it copies over the ".pdf" rows to another column or worksheet or deletes if NOT .pdf. I just want to get the ".pdf" data isolated from the rest. Please help me :(