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:       Can you tell me what bus to catch from Altadena to downtown LA ?  
 Person2:You can catch the 486 .  
 Person1:        That bus goes all the way to LA ?  
 Person2:I believe so .  
 Person1:        Is the bus ride long ?  
 Person2:It only takes 45 minutes to an hour .  
 Person1:        That's all ?  
 Person2:It's a pretty short trip .  
 Person1:        Is there always a lot of people on that bus ?  
 Person2:It only gets crowded once it gets to LA .  
 Person1:        Oh okay , thank you .  
 Person2:No problem . 

informal