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 mind taking a photo for me ?  
 Person2:Of course not .  
 Person1:        That's really kind of you .  
 Person2:I'm afraid I don't know how to use your camera .  
 Person1:        Well , it's an automatic camera . You just press the button .  
 Person2:I see .  
 Person1:        Thanks a lot . 

informal