In March 2018, Serengeti exercised an ISO that had been granted by his employer, Thunder Corporation, in December 2015. Serengeti acquired 5,000 shares of Thunder stock for the exercise price of $65 per share. The fair market value of the stock at the date of exercise was $90 per share.

If an amount is zero, enter "0".

a. What is Serengeti's 2015 AMT adjustment related to the ISO? Amount: $ _______

b. What is Serengeti's 2018 AMT adjustment related to the ISO? Amount: $ _______