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:       Hey , David . Where did you get the sofa ? It's so beautiful . Look at the color , I really love this yellow , so bright ! It must be very expensive .  
 Person2:Not really . To be honest , it's very cheap . I only spent $ 100 .  
 Person1:        Are you kidding ? $ 100 for this big leather sofa ?  
 Person2:Yes . I bought it in Johnson thrift store .  
 Person1:        Is it a used one ?  
 Person2:Yes , it is .  
 Person1:        Oh , I don't think I will buy a used sofa even it looks so attractive . 

informal