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 think we've met . 
 Person2:No , I don't think we have . 
 Person1:        My name is Dick Brown . 
 Person2:How do you do ? Mr . Brown . I am Susan Heywood . 
 Person1:        Mr . Smith often talked about you . 
 Person2:Really ? I am glad to meet you . 
 Person1:        I'm honored to know you . 

informal