On December 31, 2020, Halo Company had 500,000 shares of common stock issued and outstanding. On April 1. 2021, Halo purchased 80,000 shares of its common stock as treasury stock. Halo issued a 5% stock dividend on July 1, 2021. 60,000 shares of treasury stock were sold on November 1. What is the appropriate number of shares (i.e., the denominator) to be used in the basic earnings per share computation for 20212