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 w1, w2, naw1, nbw2;
not_gate not1 (.a(a), .y(naw1));
not_gate not2 (.a(b), .y(nbw2));
and_gate and1 (.a(a), .b(nbw2), .y(w1));
and_gate and2 (.a(naw1), .b(b), .y(w2));
or_gate org (.a(w1), .b(w2), .y(y));
endmodule