question: What are the cities that have a branch that opened in 2001 and a branch with more than 100 members?
#1 return branches 
#2 return #1 that  opened in 2001 
#3 return number of  members for each  #1 
#4 return #1 where #3 is  more than 100 
#5 return the  cities of  both #2 and  #4