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:       Mr . Li , the report has been finished . 
 Person2:So fast ! Thank you . 
 Person1:        You're welcome . This is my duty . Anything else ? 
 Person2:Yes , you'd print out the address and telephone number of those guests from your computer , and then send those materials to each business worker . 
 Person1:        OK , I'll do it right now . 
 Person2:By the way , to tell them try to persuade those new guests to cooperate with us . Because I found a biggest opponent from this post-trip . 
 Person1:        Yes , I get it . 
 Person2:OK , it's no anything . Do what you should do . 

formal