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 2018, 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 2018:

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.