64. Full Adder

How do you plan to solve it?

// Half Adder primitive
module half_adder (
    input  a, b,
    output reg sum, carry
);
    always @ (*) begin
        sum=a^b;
        carry=a&&b;  
    end

endmodule

// Full Adder using 2 Half Adders
module full_adder_struct (
    input  a, b, cin,
    output sum, cout
);
wire w1,w2,w3,w4;
    half_adder ha1(
        .a(a),
        .b(b),
        .sum(w1),
        .carry(w2)
    );
    half_adder ha2(
        .a(w1),
        .b(cin),
        .sum(w3),
        .carry(w4)
    );
    assign sum=w3;
    assign cout=w4|w2;

endmodule