module demux_1x64 (in,sel,out);
input in;
input [5:0] sel;
output [63:0] out;
wire [1:0] out_w;

demux_1x2 d64_0(.in(in),.sel(sel[5]),.out(out_w[1:0]));
demux_1x32 d64_1(.in(out_w[0]),.sel(sel[4:0]),.out(out[31:0]));
demux_1x32 d64_2(.in(out_w[1]),.sel(sel[4:0]),.out(out[63:32]));

endmodule