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:       Our company's wei-ya is tomorrow night ! It's your first Chinese New Year in Taiwan--you must be excited ! 
 Person2:Excited ? What's there to be excited about ? It's just another company dinner , right ? 
 Person1:        You have no idea ! There's a banquet with prizes , performances ... you name it ! 
 Person2:Really ? What kind of prizes ? 
 Person1:        Well , I heard that last year Vivian from accounting won a new car ! 
 Person2:A new car ! You're kidding ! 
 Person1:        No , really ! And she told me the secret to winning , wear red underwear ! 
 Person2:Wear red underwear ? ! Does that really work ? Are you going to try it ? 
 Person1:        Of course ! I'm not only going to wear red underwear , but I'm going to wear red socks and a red shirt , too ! 
 Person2:Gee , I don't think I own any red underwear , but I can buy some ! 

informal