ABC Corporation awarded John 1,000 options in 2014; each option allows him to purchase one share of ABC Corporation stock for $20. The ABC stock was selling for $18 per share at the grant date. In 2016, John exercised the options when the stocks selling price was $40 per share. In 2018, John sells the stock for $50 per share. How much gain does John recognize in 2018 when he sells the stock if they are incentive stock options?