Writing "4-1" provides information about "why this is 3?". You can say it's a calculation that documents code. When performance isn't vital in algorithms, I'd rather try to make code easier to understand.
It'd be the best if you created some sprite called "Conf" and put PV like "ElementsCount" and then done events like:
[code:1cjhwone]-> "UP" pressed: set value to (value + Conf('ElementsCount') - 1) % Conf('ElementsCount')
-> "DOWN" presset: set value to (value + 1) % Conf('ElementsCount')[/code:1cjhwone]
This'd be more flexible and useful for next appliactions.