This example takes a string containing pairs of numbers delimited by spaces (but it could be any non-numeric delimiter) and adds them into one of two lists, X and Y. A simple example for @IAmSpeed123, following this question: https://scratch.mit.edu/users/kriblo/#comments-170293271 All code by me (@kriblo). Some comments inside. The code could be made simpler, in the sense shorter, but I aimed to make it simple to read.