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:       We came too early . There're still three hours before the performance starts .  
 Person2:I know . Sorry , I shouldn't have rushed you , but I just couldn't stay at home and wait .  
 Person1:        Never mind . What about taking a look around the theater ?  
 Person2:Why not ? I'd love to do that .  
 Person1:        Here we go . There is a museum of the Beijing Opera art . ( They come to the museum of the Beijing Opera art . )  
 Person2:Wow . Look at this . So delicate and beautiful . Did ancient Chinese people really wear them ?  
 Person1:        Not really . They are just opera costumes . Do you like the embroidery ?  
 Person2:I surely do . They must have had advanced machines in ancient China to do that .  
 Person1:        No , no , no . They are all handmade , girl . You know , the ancient Chinese women were supposed to be good at needlework .  
 Person2:Unbelievable ! I could never do that .  
 Person1:        Very few can . That's why these clothes only appear in the museum .  
 Person2:Listen ! Some people are singing outside . Is it the opera ?  
 Person1:        Oh , yes . I heard there was an opera fans club . They are probably practicing now . Wanna have a look ?  
 Person2:Yes , let's do it .  
 Person1:        Follow me . Make sure not to interrupt them .  
 Person2:Of course not . We don't do that . 

informal