9. XOR Gate Using Basic Gates

How do you plan to solve it?

// ============================================================
// Basic Gates (given)
// ============================================================
module and_gate(input a, b, output y);
    assign y = a & b;
endmodule

module or_gate(input a, b, output y);
    assign y = a | b;

endmodule

module not_gate(input a, output y);
   assign y = ~a;

endmodule

// ============================================================
// XOR Gate
// ============================================================
module xor_gate (
    input  a, b,
    output y
);

    wire na,nb;
    wire a1,a2;

    not_gate not_a(a,na);
    not_gate not_b(b, nb);

    and_gate and1(b,na,a1);
    and_gate and2(a, nb,a2);

    or_gate or1(a1,a2,y);
endmodule