2 port network query

[boots_n_braces]

Hi guys and girls,
Ive got the following homework question ( i dont want answers just some help)

The drawing is attached but in case it doesn't work its a 2 port network with a 5 ohm resistor connected to each input and ground (in star fashion).

The question is, for the given z parameters for the 2 port network and with each resistor being 5 ohms show the whole circuit as a z parameter matrix.

My ideas on how to go about this

As a t network can be mapped as a 2 port network possibly its a configuration of 2 2port networks eg parallel parallel but im not sure how that would work as one network is literally inside the other.

Or do i just take the z parameter matrix and multiply by needed co efficients to take into account the series resistances for instance the input resistance would be as it is now + 5 ohm and v1 and v2 would be as they are now plus a voltage gained by inserting a 5 ohm resistor between the network and ground??

Please help im totally lost on this one!

 

[FvM]

Transforming the two-port S parameters to Z, adding the resistors and back to S is straightforward in principle. I don't expect a simple result for the general case, but I may be wrong.

Just in case you don't have the transformation formulas at hand: https://en.wikipedia.org/wiki/Impedance_parameters