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:       Could you tell me something about the Mid-Autumn Festival ? I find it also very interesting . 
 Person2:OK . It falls on the 15th day of the eighth lunar month . It is said that there is a beautiful goddess Chang'E on the moon who had eaten some sort of elixir and had to depart her husband . She is always expecting to see her husband again . So , later we have the traditional idea that when there is the full moon , it is time for the family members to come together . 
 Person1:        So , I understand why people eat moon cakes on that day . 
 Person2:You are right . In China , ' round ' is an auspicious word . The moon cakes are in round shape . 
 Person1:        Is it official ? 
 Person2:It was not in the past . But from 2008 , we can enjoy a three-day holiday for this festival . 

informal