64. Full Adder

How do you plan to solve it?

// Half Adder primitive
module half_adder (
    input  a, b,
    output sum1, carry
);
assign sum1=a^b;
assign carry=a&b;  
endmodule

// Full Adder using 2 Half Adders
module full_adder_struct (
    input  a, b, cin,
    output sum, cout
);
// first half adder/

assign sum1=a^b;
assign carry=a&b;
//second half adder//
assign sum=sum1^cin; 
assign cout= (a & b) | (b & cin) | (a & cin); 
endmodule