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:       How have you been ? 
 Person2:Fine , thank you . 
 Person1:        And how ’ s everyone in your family ? 
 Person2:Very well , thank you . I ’ m meeting my wife and daughter for lunch at 12 , would you care to join us ? 
 Person1:        I ’ d love to but I ’ m afraid I can ’ t . I ’ Ve already got a lunch engagement . 

formal