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:       Have you seen that house ?  
 Person2:Yes , it looks interesting .  
 Person1:        You're right . I love it very much .  
 Person2:It must be old .  
 Person1:        At least more than 100 years old .  
 Person2:Let's enter it !  
 Person1:        I can't open the door .  
 Person2:It must be locked .  
 Person1:        Let me ask the old woman in that reception office .  
 Person2:She can't answer you .  
 Person1:        She must be deaf .  
 Person2:It must be a haunted house . Are you frightened ?  
 Person1:        Frightened ? You must be joking . 

informal