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:       What else , Ma'am ?  
 Person2:No , thanks . My husband said , We'd like to pay now .  
 Person1:        Let me show you to the cashier's . It's 905 yuan in total .  
 Person2:What ? Where does that five come from ?  
 Person1:        Oh , it's a service charge .  
 Person2:But I only have 900 in cash here . Can you let it go for 900 yuan ?  
 Person1:        Sorry , but we can't do that . It's store's rule .  
 Person2:My husband said he had a credit card . Do you accept credit card ?  
 Person1:        Yes .  
 Person2:Great . Here it is .  
 Person1:        Here is the receipt . Wanna to have it wrapped , Ma'am ?  
 Person2:Yes , please . Thank you very much .  
 Person1:        It'll be great to have you again .  
 Person2:Thank you very much . 

informal