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:       Now I understand . But I don't smoke or drink.So what am I supposed to buy in here ?  
 Person2:You can buy some of these nice butterflies .  
 Person1:        No , I'm sorry . I don't think it is nice to have butterflies mounted in boxes.It is kind of disgusting .  
 Person2:What ? You feel sorry for the butterflies ?  
 Person1:        Yes . I think they should just let them fly free , and not try to sell them to foreigners . It is a kind of destruction of nature .  
 Person2:Well , I agree with you . I'd rather think that the butterflies are flying around in the mountains . I just wonder if they really catch so many that it affects the butterfly population .  
 Person1:        Who knows ? Hey , I like these jade bears here .  
 Person2:How much are they ?  
 Person1:        This one is 2300 dollars.Maybe I should buy it for my mother . What do you think ?  
 Person2:If you want . Didn't you buy her a small vase already ?  
 Person1:        Yes , but she would like this a lot . She likes to collect little things like this .  
 Person2:Alright . Buy it then . I won't buy anything . Well , maybe I'll buy some Cognac .  
 Person1:        Maybe I could buy some Cognac for my brother . He always drinks it .  
 Person2:Let's go ask about it . 

formal