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:       It sounds that you have a high opinion of him .  
 Person2:He is an all-right guy . I have no bone to pick with him .  
 Person1:        Birds of feather flock together .  
 Person2:But he is not a fine wether friend who could sell you down the river .  
 Person1:        You cannot judge a person that way . I have a hunch that he is a sly dog .  
 Person2:Depends on with whom . He may be doing things on the sly , but he is honest with me . I trust him .  
 Person1:        You can never tell . He might do you in when he sees an angle in doing it . 

informal