With the Increment Value action you can increment or decrement a number by any value that you want.
Incrementing a number by 1 and then -1.
All you need to configure is which column the value you want to increment is in and then how much you want to increment by. If you want to decrement a number then simply add a minus before (e.g. -1).
You can choose a custom value to increment by or you can choose a column in your sheet. When you choose a column in your sheet for the increment value, this means the number you increment or decrement by can be dynamic.