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 . Excuse me . Do you know if there's a Commercial Bank around here ?  
 Person2:Yes , go straight along Beijing Road and turn right .  
 Person1:        Straight on , and turn right . Is it far ?  
 Person2:No , it's just a couple of minutes .  
 Person1:        Thanks very much .  
 Person2:You're welcome . 

informal