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 b_not, a_not;
wire a_bnot, anot_b;
not_gate not_a (.a(a), .y(a_not));
not_gate not_b (.a(b), .y(b_not));
and_gate and1 (.a(a), .b(b_not), .y(a_bnot));
and_gate and2 (.b(b), .a(a_not), .y(anot_b));
or_gate final (.a(a_bnot), .b(anot_b), .y(y));
endmodule