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:       Hello , IMPF Bank , how can I help you ?  
 Person2:I need to report a missing Bank Card and Book .  
 Person1:        OK Sir . Could you tell me the account holder's name , the account number , the amount in the account and your PIN number , please ?  
 Person2:Well , the account's in my name . Patrick Dean , that's D-E-A-N . The account number is 15273478841 . There was about 20,000 RIB inside .  
 Person1:        OK , Sir . Almost there , I just need your PIN number . When we issue you with a new card and book we would recommend that you change your PIN number . It's a very simple procedure .  
 Person2:OK , it's 672910 . 

formal