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:       What do you like to do in your spare time ?  
 Person2:I like taking photos .  
 Person1:        Really ?  
 Person2:Yes , look at the photos I took .  
 Person1:        They are beautiful . You did a good job .  
 Person2:Thank you for saying so .  
 Person1:        As a matter of fact , you are really a terrific photographer . 

informal