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:       Wow ! That ’ s a pretty dress , but it ’ s too expensive .  
 Person2:Yeah , it is ! Why is it so expensive ?  
 Person1:        It ’ s because of good quality and the fine design .  
 Person2:I don ’ t think it ’ s worth that money .  
 Person1:        Anyhow , this dress is really elegant . 

formal