Definition: You are given a conversation between two people. 'Person1:' and 'Person2:' are used to separate their respective dialogues. You are required to assign a label 'formal' if there is an absence of emotion and a presence of questions anywhere within the conversation. If such pattern is not found assign the label 'informal'.
Input:  Person1:       Many people play sports in China , don't they ?  
 Person2:Yes . Table tennis is probably the most popular .  
 Person1:        I expect all Chinese can play table tennis .  
 Person2:Most anyway .  
 Person1:        Do you like playing table tennis ?  
 Person2:Yes , I like . But I can't play it well .  
 Person1:        Are indoor sports popular ?  
 Person2:Basketball and swimming are very popular .  
 Person1:        Really ? I like playing basketball , too .  
 Person2:We can play together if you are free .  
 Person1:        That's great . 

informal