Combine circuits A and B

Now assemble the top-level circuit from the two subcircuits of the previous problems:

• Circuit A computes z = (x XOR y) AND x.
• Circuit B computes z = x XNOR y.

The top-level design contains two copies of A and two copies of B. The top-level inputs x and y feed all four subcircuits. The outputs combine as:

z = (A1 OR B1) XOR (A2 AND B2)

where A1/A2 are the outputs of the two A copies and B1/B2 the outputs of the two B copies.

You may instantiate submodules or simply compute the intermediate signals with assign statements — both A copies (and both B copies) see the same inputs, so their outputs are identical.