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:       Hey , Daniel , how's it going ?  
 Person2:Hey , Daddy , today I had really a fantastic history class .  
 Person1:        Wow , it's so strange for you to say things like that . What had happened ?  
 Person2:We've learnt the story of Zheg He Sailing to West Ocean . He is a real great navigator .  
 Person1:        Did your teacher tell you the route he took ?  
 Person2:Yeah , he , with his fleet , came across the Indian Ocean , and arrived at the east coast of Africa .  
 Person1:        Great , do you still remember when he started his voyage ?  
 Person2:Of course , that is from 1405 to 1433 , which is in Ming dynasty .  
 Person1:        Good , by the way , do you finish reading the book Robinson Crusoe I've bought for you ?  
 Person2:Not yet , you know I have a lot of homework to do .  
 Person1:        You should speed up , because the story of Robinson can give you a better understanding about what you learned today .  
 Person2:OK , great Daddy , after supper , I'll embark on it .  
 Person1:        That's my boy ! Wait , Daniel , when is Pirates of the Caribbean on ?  
 Person2:Is it about Captain Jack Sparrow , who wants to find the treasure on the sea ?  
 Person1:        Exactly , now , tell me the time .  
 Person2:I won't tell you , unless you promise to let me watch it with you . 

informal