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: I'm not satisfied with it .
Person2:Why not ? What's wrong with it ?
Person1: Sometimes it goes fast . And sometimes it goes slow . And the alarm doesn'twork , either .
Person2:Would you like another one ?
Person1: No . Can I have my money back ?
Person2:Hmm ... have you got a receipt ?
Person1: A receipt ?
Person2:Yes . I must see your receipt . You can't have your money back without receipt .
Person1: Oh , I'm not certain , but I think I've lost it .
Output:
informal