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:       I don't know why Mark often comes to me and asks me for advice . I smell some rat in it .  
 Person2:He is sly . He is actually angling for compliments . But he may have got the crush on you .  
 Person1:        Nonsense ! There's no indication that he's in love with me .  
 Person2:Keep your fingers crossed . He may pop the question one of these days . 

informal