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:       Diana , do you like the perfume I gave you ?  
 Person2:It ’ s good . But to tell you the truth , I don ’ t wear perfume .  
 Person1:        I ’ m sorry . I didn ’ t know that .  
 Person2:That ’ s all right . Thank you all the same . 

informal