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:       Good afternoon , passport and arrival card please .  
 Person2:Here you are .  
 Person1:        Where are you coming from ?  
 Person2:China .  
 Person1:        Is this your country of birth or residence .  
 Person2:I just work there .  
 Person1:        What is the purpose of your visit to the United States ?  
 Person2:I'm here on vacation .  
 Person1:        How long do you plan to stay in the United States ?  
 Person2:Almost three weeks .  
 Person1:        Sir , you didn't fill out the information on your arrival card of where you will be staying .  
 Person2:Oh , I'm sorry , but there are a couple of different places I will travel to within the United States , so I wasn't sure what to put .  
 Person1:        You must specify an address of the place where you will spend most of your time .  
 Person2:Ok , here you are .  
 Person1:        Do you have enough means to support yourself while you are here ?  
 Person2:Yes . I have some travellers cheques and two credit cards .  
 Person1:        Very good . Do you have anything to declare ?  
 Person2:Nope . I only have my clothes and camera !  
 Person1:        Very well sir , welcome to the United States , enjoy your visit . 

formal