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:       I would like to book a table for 2 .  
 Person2:OK , sir . When will you be there ?  
 Person1:        7:00 tonight and we'd like a smoking table .  
 Person2:No problem , sir . 

informal