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:       Can I help you , sir ?  
 Person2:Yes , please . I'm picking out some presents for my children and wife .  
 Person1:        What kind of presents do you want ?  
 Person2:Actually , I don't know exactly . Do you have anything recommended ?  
 Person1:        OK . How about some very cool sneakers for your children ? Anyway , it won't cost you much . It's only around $ 59.95 for each pair . It might be cheaper than that in America .  
 Person2:Hey , How did you know I came from America ?  
 Person1:        Just a hunch , sir .  
 Person2:How much again ?  
 Person1:        $ 59.95 .  
 Person2:That's really cheap for shoes like those . OK , I'll take 5 pairs .  
 Person1:        Sorry , sir .  
 Person2:Why not ?  
 Person1:        Because in this duty-free shop , your total expenditure cannot be over $ 300 and you also have one more present to buy for your wife .  
 Person2:Oh , my God . I've totally forgotten about that . Anyway , I think she would like a bottle of perfume .  
 Person1:        That's good . And I can also recommend you a good one . It's the brand of DENY .  
 Person2:DENY ? That's very expensive in America . It costs nearly $ 70 for only 50ml.DKNY ?  
 Person1:        It's $ 60 here .  
 Person2:That's very unbelievable . Is it fake ?  
 Person1:        Of course not , sir .  
 Person2:OK , I'll take one . 

informal