Task: Question Generation
Input (English): #1 return flights 
#2 return cheapness of  flights 
#3 return #1 from  denver 
#4 return #3 to atlanta 
#5 return #4 with a stopover in pittsburgh 
#6 return #5 sorted by #2 
#7 return the  cheapest #6
Output (English): find the cheapest flight from denver to atlanta with a stopover in pittsburgh