module 1to2dec(inp, en, out);
 input inp, en;
 output out[1:0];
 wire inp_n, en_n;
 assign inp_n = ~inp;
 assign en_n = ~en;
 assign out[0] = ~(inp_n & en_n);
 assign out[1] = ~(inp & en_n);
endmodule;

module 1to2dec(inp0, inp1, en, out);
 input inp0, inp1, en;
 output out[3:0];
 wire s[1:0];
 assign s[0] = 1to2dec(.inp(inp1), .en(en))[0];
 assign s[1] = 1to2dec(.inp(inp1), .en(en))[1];
 assign out[0] = 1to2dec(.inp(inp0), .en(c[0]))[0];
 assign out[1] = 1to2dec(.inp(inp0), .en(c[0]))[1];
 assign out[2] = 1to2dec(.inp(inp0), .en(c[1]))[0];
 assign out[0] = 1to2dec(.inp(inp0), .en(c[1]))[1];
endmodule;