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:       We can't wait any longer ...  
 Person2:I'm terribly sorry to be so late . I had an article ...  
 Person1:        You'll knock yourself out the way you've worked.Why don't you slow down ?  
 Person2:I can't afford to .  
 Person1:        All right.Now that everybody's here . Shall we be getting started ? Miss Lin , are you ready ?  
 Person2:Yes , thanks.Before I start , I'd like to thank Professor Smith for all his help in giving me unlimited access to his research materials .  
 Person1:        Excuse me , Miss Lin.Would you mind speaking up , please ? I can't hear you very well .  
 Person2:Sorry , I'll try to speak louder . 

formal