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:       IMPF Bank , Li Lan speaking , how may I help you ?  
 Person2:Hello , Ms Li , this is Mr Peng .  
 Person1:        Hello , Mr Peng , how nice to hear from you again . What can I do for you today ?  
 Person2:We'll be coming in tomorrow to make a rather large cash withdrawal , it's for payroll .  
 Person1:        I see . How much exactly ?  
 Person2:500,000 RIB . Do you need me to give you my account number ?  
 Person1:        No , that's OK . I've got all of your information here on the screen in front of me . The money will be ready and waiting for you tomorrow .  
 Person2:Thanks very much for your help , Li Lan . See you tomorrow . 

informal