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:       Are you sure this is the right restaurant 。 
 Person2:Positive 。 
 Person1:        You don't think you could be wrong ? 
 Person2:I'am absolutely sure I'm right . 
 Person1:        I don't know . It looks a little wrong down . 
 Person2:This is right . There is no doubt in my mind . 
 Person1:        You're hundred percent sure you want to eat here ? 
 Person2:Check and double check . 

formal