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:       Are you having a good time ?  
 Person2:Oh , yes . It's a great party . There are some people I don't know , though .  
 Person1:        Really ? Come on , I'll introduce them to you .  
 Person2:That would be great . 

informal