In May 2021, Delos Robotics sold William an android on account for $21,000. Delos Robotics uses the accrual method. In January 2022, when the balance on the account was $18,000, William filed for bankruptcy. In June 2022, the bankruptcy trustee notified Delos Robotics that it could not expect to receive any of the amount owed to it. In 2023, the bankruptcy final settlement was made and Delos Robotics received $1,000. How much bad debt loss can Delos Robotics deduct in 2023?