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, r1 ,r2;
    not_gate n0 (.a(a),.y(na));
    not_gate n1 (.a(b),.y(nb));

    and_gate a0 (.a(a), .b(nb), .y(r1));
    and_gate a1 (.a(b), .b(na), .y(r2));

    or_gate o0 (.a(r1), .b(r2), .y(y));

endmodule