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 never understand why these shops have so much liquor .  
 Person2:What do you mean ? It's because it's much cheaper to buy liquor duty-free .  
 Person1:        But why ? Why don't people like to buy shirts duty-free ? Or shoes ? I just don't understand why it's always liquor .  
 Person2:Well , it's because in most countries liquor has a higher tax on it .  
 Person1:        You mean liquor has a higher tax than other things ?  
 Person2:Yes , of course . Didn't you know that ?  
 Person1:        No , I didn't . How high is the tax ?  
 Person2:Well , it is different in different countries.But it's because of the high tax that buying liquor duty-free is such a good deal .  
 Person1:        Why would the government want to tax liquor so much ?  
 Person2:Liquor is considered a luxury item.And also , it is considered as something that isn't very healthy.So if people want to buy it , the government thinks it has the right to tax it .  
 Person1:        That's why a lot of people buy cigarettes here too , isn't it ?  
 Person2:Of course . Cigarettes are also taxed very heavily . 

formal