module adders(P1,P2,P3);input[15:0] P1,P2;output[15:0] P3;wire cout1,cout2,cout3,cout4,cout5,cout6,cout7,cout8,cout9;wire [3:0] out1,out2,out3,out4,out5,out6;wire sel1,sel2;wire m1,m2;fouradder fouradder1(P1[3:0],P2[3:0],1'b0,P3[3:0],cout1);fouradder fouradder2(P1[7:4],P2[7:4],1'b0,out1,cout2);fouradder fouradder3(P1[7:4],P2[7:4],1'b1,out2,cout3);fouradder fouradder4(P1[11:8],P2[11:8],1'b0,out3,cout4);fouradder fouradder5(P1[11:8],P2[11:8],1'b1,out4,cout5);fouradder fouradder6(P1[15:12],P2[15:12],1'b0,out5,cout6);fouradder fouradder7(P1[15:12],P2[15:12],1'b1,out6,cout7);or(m1,cout1,cout2);and(sel1,m1,cout3);twomux twomux1(out1,out2,cout1,P3[7:4]);twomux twomux2(out3,out4,sel1,P3[11:8]);or(m2,sel1,cout4);and(sel2,m2,cout5);twomux twomux3(out5,out6,sel2,P3[15:12]);endmodule