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 ?  
 Person2:Yes , can I return this article , please ?  
 Person1:        May I know the reason , madam ?  
 Person2:You see , I bought it for my husband , but he doesn't like it .  
 Person1:        When did you buy it ?  
 Person2:Last Saturday .  
 Person1:        Can I see the receipt ?  
 Person2:Yes , here you are .  
 Person1:        Well , if there is no damage , you can return it . 

formal