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:       How do you usually sell your products now ? 
 Person2:I'm doing business through Internet now . 
 Person1:        Oh , really ? Is it a good way ? 
 Person2:Yes , very good . 
 Person1:        What advantages does it have ? 
 Person2:It is very convenient . You know you can browse the website and send e-mails to your customers at any time . 
 Person1:        Yes , if we do business through other ways , it will cost a lot of time . 
 Person2:Also it has low cost , and you know you only need to pay the fee of Internet , which is very cheap . 
 Person1:        Yes , going abroad to join the exhibition will cost much . But does it have any disadvantages ? 
 Person2:To be frank , sometimes it is not so safe as doing business through traditional ways . 
 Person1:        You mean there may be credit problems ? 
 Person2:Yes , but if you choose some good B2B websites , such problems can be avoided . 
 Person1:        Will you give some suggestion ? 
 Person2:Of course , such as the Alabama , which is a famous website . 
 Person1:        Thanks . Maybe I will do business through Internet in the future . 

informal