To further explain the purpose of MUI, MUI means multiple user interface and means simply that the script can run multiple times for multiple players at the same time without snagging or using waits in the script.
Onto your sample piece of script, considering it MUI is difficult, however I guess it can be considered MUI. Knowing more about the application of this coding would help, but in essence, it would be MUI, but also pointless. It would simply increase the integer, store it, and decrease the integer, looping endlessly. If you have any other questions about MUI coding feel free to post it and I'm sure someone here can be of assistance.