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 get you something to drink ?  
 Person2:sure , but I don't drink much . So I don't know what to order .  
 Person1:        so how about an aperitif ?  
 Person2:it sounds good . I'd like to start with a Compare .  
 Person1:        stirred or shaken ?  
 Person2:stirred will be fine .  
 Person1:        here you are .  
 Person2:thanks . Does the bar have a signature drink ?  
 Person1:        sure . All of our mixed drinks are excellent . You can also try a delicious non-alcoholic cocktail .  
 Person2:can you recommend one ?  
 Person1:        try a Singer . It has lime juice and grenadine over ice .  
 Person2:it sounds interesting . I'll take one .  
 Person1:        here we go .  
 Person2:it tastes great .  
 Person1:        enjoy yourself .  
 Person2:yeah . 

informal