Okay, probably the weirdest question this site has ever seen, but as a senior at my high school, I need help making a proposal equation for my girlfriend :)

Question

So, the idea is this: I pretend to take up and rearrange/manipulate an equation on the board in front of the class, and at the end of the equation, it ends up with something like "pʳ0ₘ=?". Very nerdy indeed, but it'll do the trick and I already know she'll love it.

So, essentially I just need a good starting equation that I can manipulate enough in order for it to spell out "prom=?" by the end of the equation. The less it resembles the word "prom" at the very start of the equation, the better, so then people won't understand what's happening until the last moment!

Any help with coming up with an equation is appreciated, as I could not find any good examples online. I still have until the summer to think about this plan, so I thought I'd ask early to get some ideas before it's too late!

Thanks so much for any help :D