On January 1, 2023 Gerald contributed $20,000 cash in exchange for a 50% capital and profits interest in Ford Partnership. During 2023, Ford had net taxable income of $50,000 and Gerald received a $15,000 distribution of cash from the partnership. Ford had $15,000 of partnership liabilities on the last day of 2023. Gerald's outside basis in his partnership interest on December 31, 2023 is