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 2017, she borrowed $50,000 on a home equity loan and used the proceeds to pay off credit card obligations and other debt. She paid the following in 2017:

Mortgage interest (personal residence)........$15,000

Mortgage interest (cottage).................................8,000

Interest on the home equity loan.......................5,000

Interest on credit card..........................................2,500

Calculate any AMT adjustment concerning interest in 2017.