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:       Happy New Year !  
 Person2:Thank you ! The same to you .  
 Person1:        Have you got any plans ?  
 Person2:I've been invited over to a friend's . And you ?  
 Person1:        My roommate's having a party . 

informal