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:       Excuse me . I've been waiting here for 15 mins . Do you know how often does No . 3 run ?  
 Person2:Oh , it runs every 20 mins . You must have missed it , when you came here . It should be here any minute now .  
 Person1:        It seems that you have got here at a good time . Do you have a bus schedule ?  
 Person2:Yes , I do . You can go to the Transport Department to get yourself a bus schedule and a bus route map .  
 Person1:        I see , thank you . 

formal