64. Full Adder

How do you plan to solve it?

// Half Adder primitive
module half_adder (
    input  a, b,
    output sum, carry
);
assign sum=a^b;
assign carry=a&b;
endmodule

// Full Adder using 2 Half Adders
module full_adder_struct (
    input  a, b, cin,
    output sum, cout
);
wire x,y,z,w;
half_adder h1(.a(a),.b(b),.sum(x),.carry(y));
half_adder h2(.a(x),.b(cin),.sum(w),.carry(z));
assign cout=z|y;
assign sum=w;


endmodule