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 ! I just want to drop in on him for a chat .  
 Person2:Please come in , Mr.Jackson .  
 Person1:        No , thank you.Please tell him to phone me when he comes back . 

informal