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 .
Output:
informal