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:       So , what happened ?  
 Person2:He never came .  
 Person1:        He stood you up .  
 Person2:I wouldn ’ t exactly characterize it in that way . I think something happened . Something terrible and unexpected that made it impossible for him to ... what if he showed up , took one look at me and left ?  
 Person1:        Not possible .  
 Person2:Maybe , there was a subway accident .  
 Person1:        Absolutely .  
 Person2:A train got trapped underground with him inside .  
 Person1:        And no phone .  
 Person2:And you know , how those express trains create suction . 

informal