F is employed by a public corporation. In year 1,F was granted a stock option to acquire 2,000 shares from the treasury of her employer's corporation for $9 a share. At the time of receiving the option, the shares were valued at $11 per share. In year 3,F exercised the option and purchased 2,000 shares for $18,000. At the purchase date in year 3 , the shares were valued at $14 per share. In year 5, F sold 2,000 shares for $19 per share. What amount is included in F's employment income for tax purposes in year 3 ? $