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 , could I ask a favour ?  
 Person2:Sure , go ahead .  
 Person1:        Could you tell me where the canteen is ?  
 Person2:Sure , I can take you there actually .  
 Person1:        Oh , I don't want to trouble you .  
 Person2:It's fine . I was heading there anyway . 

informal