George is single and had adjusted gross income of $60,000 in 2021. He paid the following in 2021: Federal income tax withholding: $8,000 State income tax withholding: $2,000 Medical expenses: $4,000 Real estate taxes: $3,000 Interest on the mortgage used for his home purchase: $7,000 Charitable contributions: $6,000 Assume he uses the best filing status for his situation, and does not have business income. What is his taxable income (Line 15) for 2021