Task: Question Generation
Input (English): #1 return flights 
#2 return #1 that  are  one way 
#3 return #2 from  pittsburgh 
#4 return #3 to atlanta 
#5 return #4 on  july twentieth 
#6 return #5 that  is  cheapest
Output (English): i'd like to book the cheapest one way flight from pittsburgh to atlanta on july twentieth