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:       Hi , Charlie ! What are you reading ?  
 Person2:Hi , bob . I ’ m reading a biography ?  
 Person1:        Who ’ s it about ?  
 Person2:It ’ s about Bob Dylan .  
 Person1:        Who is he ?  
 Person2:He ’ s a famous American musician .  
 Person1:        Who ’ s the author ?  
 Person2:It was written by Howard Sounds .  
 Person1:        What do you think about it ?  
 Person2:It ’ s great ! I ’ Ve learned a lot from reading it .  
 Person1:        Can I read it when you ’ re done ?  
 Person2:Sure , bob ! I ’ m on chapter 12 now , so I ’ m almost finished .  
 Person1:        How many chapters does the book have ?  
 Person2:There are 15 chapters in total .  
 Person1:        When do you think you ’ ll have finished reading it ?  
 Person2:I should be done by Friday . I ’ ll give it to you in class then .  
 Person1:        Thanks . Charlie !  
 Person2:No problem . Bob . 

informal