module oh_xnor4 #(parameter DW = 1 ) // array width
   (
    input [DW-1:0]  a,
    input [DW-1:0]  b,
    input [DW-1:0]  c,
    input [DW-1:0]  d,
    output [DW-1:0] z
    );
   
   assign z =  ~(a ^ b ^ c ^ d);
   
endmodule