
I would like you to implement a module named TopModule with the following
interface. All input and output ports are one bit unless otherwise
specified.

 - input  in1
 - input  in2
 - input  in3
 - output out

The module should impement the following circuit: A two-input XNOR
(connected to 'in1' and 'in2) has an output connected to the input of a
two-input XOR. The second input of the XOR is 'in3.' The output of the
XOR is 'out'.

