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:       Good evening , ma'am . May I help you ?  
 Person2:Yes . I'd like to use a safety deposit box .  
 Person1:        Will the object fit into this size of box ?  
 Person2:Let me see . I think it's OK .  
 Person1:        Could you fill out this form , please , ma'am ?  
 Person2:Here you are .  
 Person1:        Thank you , ma'am . Would you like to use it until May 20th ?  
 Person2:Yes .  
 Person1:        This way , please . Your box number is 522 .  
 Person2:Thank you .  
 Person1:        If you would like to use the contents during the period of use , please come here in person . After confirming your signature , we will open the box .  
 Person2:I see . Thank you . 

formal