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:       What's your opinion about childless couples ? Will you choose to have no kids ?  
 Person2:To be honest , I wouldn't .  
 Person1:        Why ? Do you have to make a choice now ?  
 Person2:Not really . But it has puzzled me for a long time .  
 Person1:        What's the puzzle ?  
 Person2:My husband and I prefer to have no kids , but my mother-in-law is very traditional and wants grandkids .  
 Person1:        Oh , I see . I think the older generation tend to think in a different way .  
 Person2:Yes . It seems she can never accept a childless marriage . We had a fight last night .  
 Person1:        Oh , really ? Maybe she is just eager to see her grandchildren .  
 Person2:But it's absolutely our own business to have a child or not .  
 Person1:        Definitely .  
 Person2:You know , I often overhear our neighbor , the young couple , fighting about how to raise their kid and I really don't want kids to spoil our happiness .  
 Person1:        Don't worry . I think in most cases , children are the glue that keeps a family together .  
 Person2:I guess you're right . But I still prefer to have no child .  
 Person1:        Sure . You can fully enjoy your time together . 

informal