How can you have an index that increases every time its repeated?

To add an extra level of complexity, the original index that is increased is determined by a if-then-else statement and for some reason when I set the index to "get global variable (in this case called Advice and is either 1,4, or 7) " "The operation select list item cannot accept the arguments". What is the most efficient way to solve this problem? Thanks!

*Note the highlighted block is the one I am having trouble with

Pls do not take photo with your cell phone, it's not clear.
Right click on the block area and download block image.

Advice is a number, not a list.