George purchased 100 shares of Gruber, inc. common stock for $30,000 two years ago. During the current tax year, George received a nontaxable preferred stock dividend of 50 shares. George's preferred stock had a fair market value of $4,000, and the common stock, on which the preferred stock was distributed, had a fair market value of $16,000 on the date of distribution. What is George's tax basis for his preferred stock?