9. XOR Gate Using Basic Gates

How do you plan to solve it?

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

module and_gate(input a, input b, output y);
    assign y = a & b;
endmodule

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

module xor_gate(input a, input b, output y);
    wire not_a, not_b;
    wire and1, and2;

    not_gate n1(a, not_a);
    not_gate n2(b, not_b);

    and_gate a1(a, not_b, and1);
    and_gate a2(not_a, b, and2);

    or_gate o1(and1, and2, y);
endmodule