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:       Bob is really disturbed these days .  
 Person2:We'd better have a heart-to-heart talk with him .  
 Person1:        But we cannot talk like elders .  
 Person2:Of course not . Let's talk to him in a very friendly way . 

informal