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:       Oh , boy , I hate to say this , but I really have to leave now .  
 Person2:That ’ s all right . I understand .  
 Person1:        I ’ m so sorry .  
 Person2:That ’ s ok . Don ’ t be sorry . We ’ ll talk later . 

informal