In 2009, Smith paid $6,000 to the tax collector of Big City for realty taxes on a two-family house owned by Smith's mother. Of this amount, $2,800 covered back taxes for 2008, and $3,200 covered 2009 taxes. Smith resides on the second floor of the house, and his mother resides on the first floor. In Smith's itemized deductions on this 2009 return, what amount was Smith entitled to claim for realty taxes