I'm so close I just need to know how to remove the original userNum from the output

Answer me pls is an algorithm that has been coded into something that can be run by a machine.

The open systems interconnection (osi) reference model: defines standards for many aspects of computing and communications within a network. is a generic description for how computers use multiple layers of protocol rules to communicate across a network. defines standards for wireless local area network (wlan) communication protocols. details the advantages and disadvantages of various basic network cabling options.

Description: write function lastfirst() that takes one argument—a list of strings of the format "lastname, firstname" —and returns a list consisting of two lists: (a) a list of all the last names (b) a list of all the first names