Task: Question Generation
Input (English): #1 return flights 
#2 return #1 from  any  city 
#3 return #2 to any  city 
#4 return #3 that  are one way 
#5 return fares of #4 
#6 return #5 that  is  the cheapest
Output (English): what is the cheapest one way fare from any city to another