// Half Adder primitive
module half_adder (
input a, b,
output sum, carry
);
// Write code here
xor (sum, a, b);
and (carry, a, b);
endmodule
// Full Adder using 2 Half Adders
module full_adder_struct (
input a, b, cin,
output sum, cout
);
// Write code here
wire w1, w2, w3;
half_adder h1(.a(a), .b(b), .sum(w1), .carry(w2));
half_adder h2(.a(w1), .b(cin), .sum(sum), .carry(w3));
or (cout, w3, w2);
endmodule