question: Find the list of documents that are both in the most three popular type and have the most three popular structure.
#1 return documents 
#2 return types of #1 
#3 return structures of #1 
#4 return how popular  #2 is  
#5 return how popular  #3 is  
#6 return three  most of #4 
#7 return three  most of #5 
#8 return #1 in both #6 and #7