Trouble calculating starting and ending headcount using a Loop

I have 8 months of data, starting from may 2023 until december 2023. I need to calculate the starting and ending headcount for each month. ending headcount is calculated as:

starting hc + new clients - dropped clients

starting headcount should be the ending headcount of the prior month.

I’m pretty sure i need to use a loop node (recursive?) and tried several different options to get it to work but I’m a bit lost.

Any help will be greatly appreciated!!