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:       Mr . Brown , are your children always kicking up a row like this ? I cannot concentrate on my paper .  
 Person2:Sorry , Mr . Black . I ’ m trying to make them quiet .  
 Person1:        I ’ m afraid if the noise goes on , I shall have no alternative but to leave .  
 Person2:Sorry , sir . Believe me , everything will be all right . 

formal