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:       Tom ? Oh , it's been a while since we've talked to each other . Nice to hear you again . 
 Person2:Same here . Hey , did you know Susan is going to get married . She invited me to her wedding and she wants you to attend also . 
 Person1:        Really ? 
 Person2:Definitely . I'm calling to tell you this . 
 Person1:        Why didn't she call me ? 
 Person2:She tried , but the line is always busy . 
 Person1:        Well , I may have stayed on the phone too long . Can you give me her number ? I'll call her later . 
 Person2:Of course . It's 555-4653 . 
 Person1:        Thanks . So how are things with you ? 
 Person2:Pretty good . I've just bought a new house . 
 Person1:        Wow ! Great ! Where ? 
 Person2:In the suburb . How are you and Carol ? Still living in town ? 
 Person1:        Yeah , it's really convenient . The theater and Shopping Mall are within walking distance . Well , I got to go . I'll get in touch with you soon . 
 Person2:Okay . Don't forget to call Susan . 
 Person1:        Don't worry . Bye . 

informal