/*Write your code here*/
module error_checker_xz(
input [7:0] bus,
output all_known, has_unknown,
output [7:0] bus_if_known
);
wire any_xz = (^(bus^bus) === 1'bx);
assign has_unknown = any_xz;
assign all_known = ~any_xz;
assign bus_if_known = all_known ? bus : 8'b0000_0000;
endmodule