In this performance of variable duration, the performer keeps the number of people in a room always even. For example, when there is no one in the room, the performer stays outside. When one person enters the room, the performer enters with them. When another person enters, temporarily bringing the total to 3, the performer exits, reducing the number of people in the room back to 2. Similarly, if 3 people enter the room, the performer stays inside with them to make the total number of people 4. If one of these people leaves the room, the performer exits with them, bringing the total number of people in the room back to 2.