UTCTF2021: Web: Oinker (100)

This is from the UTCTF2021 CTF

Challenge Author: a1c3

For this challenge, we are given a URL:

Going to the page gives me this:

Providing some input:

And submitting it gives me this:

I noticed that the URL has a number at the end “85”. I try to manipulate that number and see what it gives me:

I see that it gives me what appears to be previous “Oinks”. I enumerate up to get this:

And that is the flag.