How long can a UPS keep your PC running?

I'm planning to transition from a Gaming Laptop to a Gaming Desktop. I get a power cut at least once a week, it only lasts 2 to 3 minutes.

The thing is that I work from my gaming PC so I can't simply shut everything down when it happens, I was wondering how long will a good UPS keep keep things running? It doesn't have to be everything, just CPU and maybe a portable monitor.