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:       Did you remember to bring back that software I lent to you ?  
 Person2:Oh , I ’ m sorry . It completely slipped my mind .  
 Person1:        That ’ s ok . If you could just bring it in tomorrow , I would appreciate it .  
 Person2:Definitely , I ’ m really sorry . 

informal