John is a teacher at a local high school. During 2017 and 2018, he travels three days per week to a school in the next county to work with gifted children in an after-school program that does not end until 6:30 p.m. He normally eats dinner before driving home. If he drives 75 miles each way on 90 days each year to the gifted program, his annual meal expense is $900, and he maintains adequate records, how much may John deduct for these trips in 2017 and 2018?