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:       Excuse me . Could you tell me how to get to the library ?  
 Person2:Of course . It's on Memorial Avenue .  
 Person1:        On Memorial Avenue ?  
 Person2:Right . You know where that is ?  
 Person1:        I'm afraid I don't . I'm quite new in town .  
 Person2:Well , do you know where the post office is ?  
 Person1:        No , I don't . But I do know where the shopping mall is .  
 Person2:That won't help us . Let me see now ... Why don't you follow this street , Elm , until , you get to the second stoplight .  
 Person1:        Well , thank you very much , I hope I can find it . 

informal