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:       Did you say you saw lily alone ? 
 Person2:Yes , nobody was with her . 
 Person1:        Where did you say she was ? 
 Person2:In Thailand . 
 Person1:        I must say I think that is very odd . Are you absolutely certain it was her ? 
 Person2:Yes . yes , I am sure . 
 Person1:        Because I don't want any , er , do you understand ? But you are quite sure , are you ? 
 Person2:Quite sure . I mean that hair of hers and the voice of hers . 

formal