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:       Is that your phone ?  
 Person2:Yes , it's my new business phone . Do you like it ?  
 Person1:        It's very impressive . Can you use the Internet on your phone ?  
 Person2:Yes , it's got wireless Internet access .  
 Person1:        That's really convenient . Does it have the Bluetooth ?  
 Person2:Yes , but I don't really use it often . Have you ever used it ?  
 Person1:        No , but I think it'd be really great for people like you who are always on the go .  
 Person2:Yes , I guess I should try to use it . 

informal