Task: Question Generation
Input (English): #1 return the  Sverris saga  
#2 return the  Bagler sagas  
#3 return the  Håkon Håkonsson saga  
#4 return years treated in  detail of #1 
#5 return years treated in  detail of #2 
#6 return years treated in  detail of #3 
#7 return number of  #4 
#8 return number of  #5 
#9 return number of  #6 
#10 return sum of #7 ,  #8 ,   #9
Output (English): How many years are treated in detail in contemporaneous sagas: Sverris saga, the Bagler sagas, and Håkon Håkonsson's saga?