A very high probability you'll arrive and depart from a G or H gate. if you have a window seat you'll see A and B on the actual aerobridges themselves - with A corresponding to G (A when used as domestic, G when international - international departures funnel from the level above), B corresponds to H. The "first" lounge is at the C gates which will require a train - and one of the two is out of commission now so the waits can be a bit longer these days.