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. How much is their allowable medical expense deduction for 2023