coin balance system working twice

https://dropmefiles.com/27IRo

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I work in MCreator 2020.2.
I wanted to create a mod for a server with friends that adds a coin balance system, so we could make cool vending machines for resources for version 1.14.4.
I created a variable that stores information while the game is running.

The main problem:
At first I did everything without using an if statement, and it simply subtracted and added values. But I noticed that in the game it subtracts -32 from the variable instead of -16.
I searched for solutions to this problem on the internet, added an if statement — and now nothing works at all, which is pretty sad