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 , Bill .  
 Person2:Happy New Year , Steven .  
 Person1:        Do you have any plans for the New Year holiday ?  
 Person2:My whole family are going to Hainan for visiting . What about you ?  
 Person1:        How happy you are ! I have to stay at home to prepare my final exam . 

informal