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:       Hello , could I make a reservation ? 
 Person2:Sure . At what time ? 
 Person1:        6 o'dock in the evening . 
 Person2:Let me see ... Sorry , sir . We are fully booked tonight . Would you mind making a reservation some other time ? 
 Person1:        Do you offer mutton hot pot at noon ? 
 Person2:Yes , sir . 
 Person1:        Then we will come here for lunch tomorrow . 

informal