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:       The idea about Friday the Thirteenth is totally ridiculous . I don't believe it at all .  
 Person2:Maybe you can't be so sure .  
 Person1:        Why not ? The whole idea is superstitious .  
 Person2:But some people use this occasion to create trouble . Have you heard of the Black Friday Virus on the computer ? It is designed to break out on every Friday the Thirteenth .  
 Person1:        I know that . But that has nothing to do with being unlucky . Those who created the virus are deliberately making fun of people . 

formal