On July 1 of the current year, Ambrose was admitted to the partnership of Ambrose and Nectar. His contribution to capital consisted of 500 shares of stock in Paniculata Corporation, which he bought in 2014 for $10,000 and which had a fair market value of $50,000 on July 1 of the current year. Ambrose's interest in the partnership's capital and profits is 25 percent. On July 1 of the current year, the fair market value of the partnership's net assets (after Ambrose was admitted) was $200,000. What is Ambrose's taxable gain in the current year on the exchange of stock for his partnership interest