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 have a terrible toothache . 
 Person2:Which tooth is it ? 
 Person1:        ( Pointing ) This one here . 
 Person2:Ah , yes . There's big cavity . 
 Person1:        Can you fill it ? 
 Person2:I'm afraid not . The tooth is too far gone . It'll have to be taken out . 
 Person1:        Then I might as well have it out now . 
 Person2:You'd better wait . The gums are swollen . Take the medicine I prescribe and come back in three days . 

informal