64. Full Adder

How do you plan to solve it?

// Half Adder primitive
module half_adder (
    input  a, b,
    output sum, carry
);
    assign {carry,sum} = a+b;
endmodule

// Full Adder using 2 Half Adders
module full_adder_struct (
    input  a, b, cin,
    output sum, cout
);
    wire ha1_sum, ha1_carry, ha2_carry;
    half_adder HA1 (.a(a)      , .b(b)  , .sum(ha1_sum), .carry(ha1_carry));
    half_adder HA2 (.a(ha1_sum), .b(cin), .sum(sum)    , .carry(ha2_carry));

    assign cout = ha1_carry | ha2_carry;
endmodule