module demux_1x4 (in,sel,out);
input in;
input [1:0] sel;
output [3:0] out;
wire [1:0]out_w;

demux_1x2 d4_0(.in(in),.sel(sel[1]),.out(out_w));
demux_1x2 d4_1(.in(out_w[0]),.sel(sel[0]),.out(out[1:0]));
demux_1x2 d4_2(.in(out_w[1]),.sel(sel[0]),.out(out[3:2]));


endmodule 