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:       What are you listening now , Fred ?  
 Person2:What ?  
 Person1:        Hey ! Man , put your earphone out . I said which song you are listening to .  
 Person2:Jay Chou's title song in his new album .  
 Person1:        What's your comment on his new album ?  
 Person2:Gorgeous ! There is another song combining Chinese and western music styles . I am crazy for it , so I hear it over and again . And I plan to make it as the ringbone of my mobile .  
 Person1:        Let me enjoy it .  
 Person2:I suppose this song can be the No . 1 on the top chart .  
 Person1:        I cann't wait for buying his CD now . 

informal