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'd like to reserve a table for three at 6:30 this evening . 
 Person2:Let me check . Hold on , please ... Yes , that's fine . Smoking or nonsmoking area ? 
 Person1:        Nonsmoking , please . 
 Person2:All right . May I have your name ? 
 Person1:        My surname is Gao . 
 Person2:How do you spell it , sir ? 

formal