Twig PHP: Increase and Subtract Value in Foreach
I am working on a project that repeats 100 times with duplicate data. Every eighth post I insert an ad unit because I am using the index value for the number of each output unit, which needs to be subtracted from the variable, because the ad unit is not numbered. So, the problem I am currently having is the following:
Block #1 Block #2 Block #3 Block #4 Block #5 Block #6 Block #7 Advertisement Block Block #9
Since it counts the ad unit as one iteration of the index, the subsequent block that will have a number is now 9 when it should be 8. Is there any way to increase the value of the variable and then subtract the value 1 from it every time the ad is displayed block?
In standard PHP I could do this easily, but with Twig I have tried a few things and am not sure what I can do.
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