A1: Join hands: go in to the middle and back. And again.
A2: Women in three steps, clap; fall back. Men in, clap; turn left and go back to corner (new partner).
B1: Swing.
B2: Promenade.
You can also vary it - instead of going to your corner, swing someone on the other side of the room. Men go in first and then the women decide who to swing. It's good to finish with “Find your original partner to swing”.