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:       Can I borrow your Cds for our school dance ?  
 Person2:Oh , you don't ask much , do you ?  
 Person1:        I promise I will personally guard every single one and they will come back in perfect condition .  
 Person2:I'll tell you what . Your class can rent them from me for the night and buy back any damaged ones .  
 Person1:        That sounds fair . That's still cheaper than paying a band to come play for us .  
 Person2:Not as fun though . A live band is way more exciting !  
 Person1:        Our class doesn't have enough money . We already checked into it .  
 Person2:Let me know with your next dance . I know a band that may give you a break for the publicity . 

formal