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:       May I help you ?  
 Person2:I can ’ t find the book I want .  
 Person1:        Why don ’ t you try looking at the database ?  
 Person2:I checked it already .  
 Person1:        Do we have it available ?  
 Person2:It wasn ’ t there .  
 Person1:        I guess it is lost .  
 Person2:Will you be getting another copy ?  
 Person1:        Yes , we will .  
 Person2:Could you reserve a copy for me ?  
 Person1:        I can do that .  
 Person2:That ’ s great . Thanks a lot . 

informal