Task: Question Generation
Input (English): #1 return flights 
#2 return #1 from  washington dc 
#3 return #2 to  san francisco 
#4 return #3 after 5pm 
#5 return #4 on  november twelfth 
#6 return #5 in economy class
Output (English): all flights from washington dc to san francisco after 5pm on november twelfth economy class