SUSI(35) is single. Her 2020 federal itemized deductions totaled $14,400, of which she claimed $1,000 of state income taxes paid in 2020. She filed her tax return on April 10, 2021, and on May 1, 2021, she received a $1,000 state income tax refund. How much of her 2020 state refund is taxable on her 2021 federal return