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:       Where should I sit ?  
 Person2:Why don't you sit in the back with me ?  
 Person1:        Okay .  
 Person2:By the way , what's your last name ? I forgot what it is .  
 Person1:        It's Lin . It's spelled L-I-N .  
 Person2:R-I-N ?  
 Person1:        My pronunciation is not very good . It's L-I-N , Lin .  
 Person2:I got it . Mary Lin .  
 Person1:        Lin is a common Chinese last name . 

formal