There can be only on, MAYBE two.
Two 8-Switch Useless Machines Battle It Out

This is a video of two useless machines having an intense switching battle. For those of you unfamiliar, a useless machine is a machine designed to unflip a switch when it’s flipped, and nothing else. In this case, two 8-switch useless machines connected to each other’s switches via rods constantly battle to turn their own switches off. How exciting! I was really hoping one would malfunction and catch fire, but if there’s one thing life has taught me, it’s never get your hopes up.