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:       How is your appetite today ? 
 Person2:I'm rather hungry now . 
 Person1:        What would you like to have ? 
 Person2:Please give me a piece of pie first . 
 Person1:        Which would you rather have , beef or chicken ? 
 Person2:Beef , please . 
 Person1:        How about drinks ? Coffee or tea ? 
 Person2:Coffee , please . 
 Person1:        Do you want to take milk and sugar ? 
 Person2:Only black coffee . 

formal