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:       Who got ripped off ?  
 Person2:Big time ! A hacker broke into the company's files and got all her personal information . You really think it's completely safe ?  
 Person1:        Well , maybe not 100 percent . I did hear about some tricks people use .  
 Person2:Now we're getting to the truth .  
 Person1:        There are shills . A shill is someone who bids up the price of their own sale .  
 Person2:See ? And I bet that's easy to do online . Everybody's anonymous . 

informal