A keyboard, video, mouse (KVM) switch would allow you to use one keyboard, one monitor, and one mouse for all three computers in your office. A KVM switch is a device that enables you to control multiple computers using a single set of peripherals, such as a keyboard, mouse, and monitor. By connecting the KVM switch to each of the computers in your office, you can use the same set of peripherals to control all of the computers, switching between them as needed. This allows you to work more efficiently and reduces the time it takes to move between computers. Some KVM switches also allow you to control computers over a network, so you can access them remotely.