Barbara is single and owns a home in the city, which is her primary residence. She also owns a cottage at the beach, which she treats as a vacation home. In April 2021, she borrowed $80,000 on a home equity loan and used the proceeds to pay off credit card obligations and other debt. She paid the following in 2021: Required: Calculate any AMT adjustment concerning interest in 2021. Note: Input all the values as positive numbers. Leave no cells blank - be certain to enter "O" wherever required