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:       Do you often surf the Internet ?  
 Person2:Yeah . I do it once a week .  
 Person1:        Is it very interesting ?  
 Person2:Sure . I get a lot of information and make many friends .  
 Person1:        Oh , I'll have a try . 

informal