chicago is connected to List (first-->last): 
boston
iowa city
milwaukee
boston is connected to List (first-->last): 
cedar rapids
chicago
iowa city is connected to List (first-->last): 
milwaukee
chicago
cedar rapids is connected to List (first-->last): 
boston
milwaukee is connected to List (first-->last): 
iowa city
chicago
--------------------------------
chicago 0.3333333333333333
boston 0.0
iowa city 1.0
cedar rapids 1.0
milwaukee 1.0