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 .  
 Person2:Mark , this is Lucy .  
 Person1:        What's up ?  
 Person2:I have a friend . He is my best friend and he wants to learn English . He would pay about 100 yuan per hour . Are you interested ?  
 Person1:        I don't know .  
 Person2:So I take it you are not interested .  
 Person1:        No , Lucy . Don't get me wrong . I mean school will be open on Sept . 2nd , and I will have a very tight schedule by then .  
 Person2:Don't worry . My friend says he can always arrange his schedule around your schedule .  
 Person1:        That will be fine . When can I see him ?  
 Person2:Let's do it this way . I'll take him to your place this Saturday . Then you two can make a schedule .  
 Person1:        Make sure you come here before noon . I will be picking up my friend at the airport in the afternoon .  
 Person2:How are you going to get there ?  
 Person1:        By bus , of course .  
 Person2:I am sure my friend can give you a ride .  
 Person1:        Great . By the way , what does your friend do ?  
 Person2:He is a lawyer .  
 Person1:        Ok , see you then .  
 Person2:See you . 

formal