Melissa recently paid $805 for round-trip airfare to San Francisco to attend a business conference for three days. Melissa also paid the following expenses: $360 fee to register for the conference, $395 per night for three nights lodging, $140 for meals, and $540 for cab fare. (Leave no answers blank. Enter zero if applicable. Do not round intermediate calculations. Round your final answer to the nearest dollar amount.)

c. Suppose that Melissa made the trip to San Francisco primarily to visit the national parks and only attended the business conference as an incidental benefit of being present on the coast at that time. What amount of the airfare can Melissa deduct as a business expense?