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:       I believe that you called me ?  
 Person2:Oh , hi . Thanks for getting back to me quickly .  
 Person1:        Why did you call me ?  
 Person2:I was calling about your son .  
 Person1:        Did he do something wrong ?  
 Person2:Your son was acting up in class .  
 Person1:        What do you mean ?  
 Person2:He was talking and causing a disturbance during class .  
 Person1:        That's really not like him .  
 Person2:If you could just talk to him , I would greatly appreciate it .  
 Person1:        I apologize , and I'll make sure he doesn't do that again .  
 Person2:Don't worry about it , but thank you very much . 

informal