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:       Excuse me , we have book table 6 . Would you please come and tidy the table ?  
 Person2:OK , sir . We will be there right now ... sir , your table is ready .  
 Person1:        Thank you . Could we have the menu , please ?  
 Person2:Sure , here you are . 

informal