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 here to conduct the annual census of foreigners living in Beijing . This is my service ID card .  
 Person2:OK.What do you want to know ?  
 Person1:        We only need to verify your information against our records .  
 Person2:OK .  
 Person1:        Please show me your passport and Residence Permit .  
 Person2:Here you are .  
 Person1:        How long have you been living here ?  
 Person2:Two years .  
 Person1:        May I know your occupation ?  
 Person2:I'm a professor at a university .  
 Person1:        Is that right ? Which university , if you don't mind my asking ?  
 Person2:I teach at Beijing Normal University , English composition and some conversational classes .  
 Person1:        Everything appears to be in order . Thank you for your time . 

formal