context: When my girlfriend and I decided to take a vacation to Florida and we knew we needed to make flight reservations.  We went online and looked at our favorite airline to see what flights they had to Florida the day we wanted to leave and a flight the day wanted to come home.  We found flights we wanted and set to making our reservation.  We made sure the flights we liked had two seats available, and we got to choose where on the airplane we got to sit.  We choose two seats together in row 10, a window seat and a middle.  While the middle seat isn't as much fun as the window it meant we could sit together.  Now that we had our seats, for the way there, we then picked out seats for the way home and we were able to pick the same ones.  Now with both flights selected, we went to the payment page and paid for the seats with a credit card.  With the flights paid for, we could print out our tickets for our trip to Florida.
question: How many tickets did they need?
reference: 2 each way, 4 total
candidate: The two that came with the ticket.