Pivot, subtraction based on filters

[Daktari]

Hello,
I'm having a list which adds one row for each action. Ie one row for adding item X, and one row for removing item X. I can filter based on add and remove.
I'm trying to create a calculated field in a pivot; NET ADD; Sum of Action filtered add, subtracted for action filtered remove.

I'm summarizing this by week, and since the weeks of add and remove don't always sync up, I can't use absolute references.

I'm struggling with the syntax in calculated field. I would love some help.

 

[Daktari]

My quick fix was to create a dummy column next to my input with an if formula [+1, 0, -1] and summarizing.
Still interested in calculated field manipulations, though I solved my issue short term.