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 have my money back on this skirt ?  
 Person2:Anything wrong with it ?  
 Person1:        Yes , this is defective . See ? I didn't notice this hole when I bought it .  
 Person2:Oh , I'm very sorry about that . You can change it for another one if you prefer .  
 Person1:        If you have exactly the same one-same color , same design , and same size , of course .  
 Person2:This one is the same size and color . But the design is different . 

informal