Tracking multiple dependencies

Hey all,

I am looking for a formula that is able to track the iteration of products from their source. It is difficult to explain, so I attached an example. In the attached document, I am looking for a formula in the range F4:F13 that will be able to look at the ID numbers in column E, and be able to trace related iterations through to their source, or first iteration. Column E shows the link between a new product and its last iteration and will be input by users, but cannot track any further beyond that. From there, I need to be able to track how many iterations a product has gone through (column G).

I included an example of what it should look like if the formula is possible. Any help would be appreciated!

Cheers,
B