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:       Hello , there . How can I help ? 
 Person2:Hello . I'm hoping to buy some Treasury Certificates today . Are they available ? 
 Person1:        Certainly , Visible Treasury Certificates . Then you can get a receipt from the savings office as proof of payment . Hence the ' visible ' , you can see it . 
 Person2:Ah , right . How much do I need to spend ? 
 Person1:        The minimum is 100 RIB , and the maximum is 500,000 RIB . 
 Person2:How about Bearer Certificates ? Are they different ? 
 Person1:        Yes , they are different because they are printed by the Ministry of Finance in set amounts . Just 100 RIB , 500 RIB and 1,000 RIB , you cannot choose from many amounts , you see . 

formal