Mann Inc., had 360,000 shares of common stock issued and outstanding on January 1. On July 1, an additional 60,000 shares of common stock were issued for cash. Mann also had unexercised stock options to purchase 48,000 shares of common stock at $15 per share outstanding at the beginning and throughout the year. The average market price of Manns common stock was $20 during the year. What is the number of shares that should be used in computing diluted earnings per share for the year ended December 31?