Roger (age 45) and Cindy (age 44) Johnson are married, file a joint return, and have AGI of $80,000 in 2023. During 2023, they paid $18,000 for the following qualified medical expenses: doctor bills, hospital expenses, medical insurance, and prescription medicine. In January, 2024, the Johnsons received an insurance reimbursement of $4,000 for the 2023 doctor bills and hospitalization expenses. Using the facts assuming that the Johnsons' itemized deductions totaled $29,900 in 2023. How much, if any, of the $4,000 insurance reimbursement will be included in their gross income for 2024?