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:       Housekeeping . May I help you ?  
 Person2:Yeah , the people in the next room are a little loud . Could you do something about it ?  
 Person1:        Of course . What room are you in , sir ?  
 Person2:I'm in Room 215 .  
 Person1:        And do you know which room the noise is coming from ?  
 Person2:I don't know the number , but it's definitely the room that's next to the stairs .  
 Person1:        Thank you . We'll take care of it . Please let us know if there's anything else we can do to make your stay more comfortable .  
 Person2:OK , thanks . I really appreciate it . 

informal