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:       Excuse me . Is there any body here ?  
 Person2:Yes .  
 Person1:        I've finished up all my water . I would kill for a sip of water .  
 Person2:Sure , come on in .  
 Person1:        Thank you very much . Are you here alone ?  
 Person2:My father and sister are out to photographing . What about you ?  
 Person1:        I'm a back-packer from America .  
 Person2:What is a back-packer ?  
 Person1:        It means a hiker who loves traveling around the world .  
 Person2:Cool . You must have been to a lot of places .  
 Person1:        Yes , actually almost half of all the countries over the world . I love traveling places .  
 Person2:So cool . I want to be a back-packer when I grow up .  
 Person1:        You can do it . But do work hard on your English to make it easier .  
 Person2:I'll try my best . 

informal