i would like the flight number and the time for the cheapest fare that is the least expensive first class fare from san francisco to pittsburgh leaving after 8 pm monday night
O O O O O O O O B-flight_time O O B-cost_relative O O O O B-cost_relative I-cost_relative B-class_type I-class_type O O B-fromloc.city_name I-fromloc.city_name O B-toloc.city_name O B-depart_time.time_relative B-depart_time.time I-depart_time.time B-depart_date.day_name B-depart_time.period_of_day