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:       Why aren't you doing your homework ?  
 Person2:I'll do it later , Dad . I must prepare the concert on Saturday .  
 Person1:        Oh , is it ? You'll be making records next , will you ?  
 Person2:We hope so .  
 Person1:        You'd better get on with your homework ! You can practice on Sunday .  
 Person2:Oh dad . You don't understand at all .  
 Person1:        I certainly could . You'll get exams next month .  
 Person2:I don't need it to play the guitar .  
 Person1:        Oh , don't you ? God save me !  
 Person2:I'm sorry . 

informal