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:       Well , I'm thinking of going to see the ballet Swan Lake by the famous Russian National Ballet Troupe this evening at Beijing Grand Theater . Why don't you join me ?  
 Person2:I'd like to , but I've got to write a term paper . It will be due by this Thursday .  
 Person1:        You always work too hard , Jim . As the saying goes , all work and no play makes Jack a dull boy . You should spare some time for a rest .  
 Person2:I know it is no good for my health if I am staying in the classroom all day . But how about my paper ?  
 Person1:        Just take it easy . Come on with me .  
 Person2:I'm terribly sorry I can't go with you . Shall we find some other time ? 

formal