Detailed Instructions: 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'.
Q: 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 .
A:
informal