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:       I went to Rotes ’ , you know , Edith Roth is the author of a book about moths .  
 Person2:Is she ? I thought she was a mathematician .  
 Person1:        I ’ m so thirsty .  
 Person2:Are you ? I thought you had something to drink at her home .  
 Person1:        No . Edith didn ’ t give anything to drink .  
 Person2:I ’ ll buy you a drink .  
 Person1:        Oh ! Thank you . 

informal