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:       Excuse me . We ordered too much . May we take the food home ?  
 Person2:Yes , surely .  
 Person1:        Do I have to pay extra charge for that ?  
 Person2:No , you don't . It is free of charge .  
 Person1:        Well , then , will you put this and that into doggie bags ?  
 Person2:Certainly , would you wait for a few minutes ?  
 Person1:        Thanks . Would you give me another favor ?  
 Person2:Yes , what is it ?  
 Person1:        Some more Chinese tea for us , please .  
 Person2:Sure , I'll be back in a minute . 

informal