Zack was the beneficiary of a life insurance policy on his wife. Zack had paid $20,000 in premiums on the policy. He collected $50,000 on the policy when his wife died from a terminal illness. Because it took several months to process the claim, the insurance company paid Zack $53,000, the face amount of the policy plus $3,000 interest. How much income must Zack include in his gross income?